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1

New Bedford Harbor Superfund Project, Acushnet River estuary engineering feasibility study of dredging and dredged-material disposal alternatives. Report 11. Evaluation of conceptual dredging and disposal alternatives. Technical report, August 1985July 1988  

Microsoft Academic Search

This report evaluates conceptual dredging and disposal alternatives for the Acushnet River Estuary, a part of the New Bedford Harbor Superfund Site. Dredging for removal of the highly contaminated sediment and subsequent disposal in upland or nearshore confined disposal facilities or disposal in contaminated aquatic disposal facilities are alternative considered in the Engineering Feasibility Study of Dredging and Dredged Material

D. E. Averett; M. R. Palermo; M. J. Otis; P. B. Rubinoff

1989-01-01

2

Deschutes Estuary Feasibility Study; Hydrodynamics and Sediment Transport Modeling  

USGS Publications Warehouse

Continual sediment accumulation in Capitol Lake since the damming of the Deschutes River in 1951 has altered the initial morphology of the basin. As part of the Deschutes River Estuary Feasibility Study (DEFS), the United States Geological Survey (USGS) was tasked to model how tidal and storm processes will influence the river, lake and lower Budd Inlet should estuary restoration occur. Understanding these mechanisms will assist in developing a scientifically sound assessment on the feasibility of restoring the estuary. The goals of the DEFS are as follows. Increase understanding of the estuary alternative to the same level as managing the lake environment. Determine the potential to create a viable, self sustaining estuary at Capitol Lake, given all the existing physical constraints and the urban setting. Create a net-benefit matrix which will allow a fair evaluation of overall benefits and costs of various alternative scenarios. Provide the completed study to the CLAMP Steering Committee so that a recommendation about a long-term aquatic environment of the basin can be made. The hydrodynamic and sediment transport modeling task developed a number of different model simulations using a process-based morphological model, Delft3D, to help address these goals. Modeling results provide a qualitative assessment of estuarine behavior both prior to dam construction and after various post-dam removal scenarios. Quantitative data from the model is used in the companion biological assessment and engineering design components of the overall study. Overall, the modeling study found that after dam removal, tidal and estuarine processes are immediately restored, with marine water from Budd Inlet carried into North and Middle Basin on each rising tide and mud flats being exposed with each falling tide. Within the first year after dam removal, tidal processes, along with the occasional river floods, act to modify the estuary bed by redistributing sediment through erosion and deposition. The morphological response of the bed is rapid during the first couple of years, then slows as a dynamic equilibrium is reached within three to five years. By ten years after dam removal, the overall hydrodynamic and morphologic behavior of the estuary is similar to the pre-dam estuary, with the exception of South Basin, which has been permanently modified by human activities. In addition to a qualitative assessment of estuarine behavior, process-based modeling provides the ability address specific questions to help to inform decision-making. Considering that predicting future conditions of a complex estuarine environment is wrought with uncertainties, quantitative results in this report are often expressed in terms of ranges of possible outcomes.

George, Douglas A.; Gelfenbaum, Guy; Lesser, Giles; Stevens, Andrew W.

2006-01-01

3

New Bedford Harbor Superfund Project, Acushnet River estuary engineering feasibility study of dredging and dredged-material disposal alternatives. Report 12. Executive summary. Final report  

SciTech Connect

Sediments in New Bedford Harbor, Massachusetts, have been contaminated with polychlorinated biphenyl compounds and heavy metals. The high levels of contamination have resulted in the New Bedford site being placed on the National Priorities List of the Nation's worst hazardous waste sites. The US Army Corps of Engineers has been working since 1986 in efforts to evaluate remedial action alternatives for this site. The purpose of the EFS was to evaluate the engineering feasibility of dredging and selected disposal alternatives for removal and disposal of contaminated sediment from the New Bedford Superfund Site. Results of the EFS are presented in a series fo 12 reports. Reports 1-11 present detailed results of field investigations, laboratory studies, and engineering analyses. This executive summary highlights information from the first 11 reports and presents results of the EFS.

Averett, D.E.; Otis, M.J.

1990-01-01

4

Journal of Engineering Mathematics Optimal discharging in a branched estuary Optimal discharging in a branched estuary  

E-print Network

Journal of Engineering Mathematics Optimal discharging in a branched estuary Optimal discharging for the optimal discharge rate. If cross-sectional mixing within each branch of the estuary takes place more in a branched estuary R. SMITH Department of Mathematical Sciences, Loughborough University, LE11 3TU, U.K. e

5

Estuaries  

NSDL National Science Digital Library

Estuaries are bodies of water and their surrounding coastal wetlands typically found where rivers meet the sea. Estuaries harbor unique plant and animal communities because their waters are brackish--a mixture of fresh water draining from the land and salty seawater.Estuaries are some of the most productive ecosystems in the world. Many animal species rely on estuaries for food, places to breed, and migration stopovers. Human communities also rely on estuaries for food, recreation, jobs, and coastal protection.Of the 32 largest cities in the world, 22 are located on estuaries (e.g., New Orleans, London, etc). Not surprisingly, human activities have led to the decline in the health of estuaries, making them one of the most threatened ecosystems on the Earth. NOAA's National Estuarine Research Reserve System in partnership with coastal states monitors the health of estuaries and helps communities manage their coastal resources.

Educator, Laura K.; National Science Teachers Association (NSTA); Review, Steve W.

2005-04-01

6

New Bedford Harbor Superfund Project: Acushnet River Estuary engineering feasibility study of dredging and dredged-material disposal alternatives. Report 2. Sediment and contaminant hydraulic transport investigations. Technical report, February 1986-July 1987  

SciTech Connect

This report documents the evaluation of hydraulic conditions and sediment migration associated with the dredging and dredged material disposal alternatives proposed for the upper Acushnet River Estuary upstream of New Bedford Harbor, Massachusetts. Dredging and onsite disposal is one remedial measure being considered by the US Environmental Protection Agency. Assessments of sediment and contaminant migration beyond the upper New Bedford Harbor from proposed dredging and disposal alternatives were made based on field, laboratory, and various model studies. The upper estuary was found to be depositional and a reasonably efficient sediment trap. Total suspended material (TSM) concentrations were very low in the system.

Teeter, A.M.

1988-12-01

7

New Bedford Harbor Superfund Project: Acushnet River Estuary engineering feasibility study of dredging and dredged-material disposal alternatives. Report 2. Sediment and contaminant hydraulic transport investigations. Technical report, February 1986July 1987  

Microsoft Academic Search

This report documents the evaluation of hydraulic conditions and sediment migration associated with the dredging and dredged material disposal alternatives proposed for the upper Acushnet River Estuary upstream of New Bedford Harbor, Massachusetts. Dredging and onsite disposal is one remedial measure being considered by the US Environmental Protection Agency. Assessments of sediment and contaminant migration beyond the upper New Bedford

Teeter

1988-01-01

8

New Bedford Harbor Superfund Project Acushnet River estuary engineering feasibility study of dredging and dredged-material disposal alternatives. Report 10. Evaluation of dredging and dredging control technologies. Technical report, August 1985March 1988  

Microsoft Academic Search

This report presents the results of an evaluation of dredging equipment and techniques for removal of highly contaminated sediments from the upper estuary of the Acushnet River, a portion of the New Bedford Harbor Superfund Project. Site conditions as related to dredge selection and operation, factors considered in selection of equipment, various dredge types considered for use, and operational procedures

M. R. Palermo; V. R. Pankow

1988-01-01

9

New Bedford Harbor Superfund Project, Acushnet River estuary engineering feasibility study of dredging and dredged-material disposal alternatives. Report 1. Study overview. Technical report, August 1985March 1988  

Microsoft Academic Search

Sediments in the New Bedford Harbor and Acushnet River Estuary have been contaminated with polychlorinated biphenyl compounds and heavy metals. The high levels of contamination have resulted in the New Bedford Harbor being placed on the National Priorities List of the Nation's worst hazardous waste sites. Efforts are under way to develop and implement remedial actions for protection of the

N. R. Francingues; D. E. Averett; M. J. Otis

1988-01-01

10

Artemis: Results of the engineering feasibility study  

NASA Technical Reports Server (NTRS)

Information is given in viewgraph form for the Engineering Feasibility Study of the Artemis Project, a plan to establish a permanent base on the Moon. Topics covered include the Common Lunar Lander (CLL), lunar lander engineering study results, lunar lander trajectory analysis, lunar lander conceptual design and mass properties, the lunar lander communication subsystem design, and product assurance.

1991-01-01

11

New Bedford Harbor Superfund Project Acushnet River estuary engineering feasibility study of dredging and dredged-material disposal alternatives. Report 10. Evaluation of dredging and dredging control technologies. Technical report, August 1985-March 1988  

SciTech Connect

This report presents the results of an evaluation of dredging equipment and techniques for removal of highly contaminated sediments from the upper estuary of the Acushnet River, a portion of the New Bedford Harbor Superfund Project. Site conditions as related to dredge selection and operation, factors considered in selection of equipment, various dredge types considered for use, and operational procedures and controls for sediment resuspension during dredging are described. Each of the dredge types is ranked according to the following criteria: compatibility for full-scale cleanup, availability, safety, potential for sediment resuspension, maneuverability, cleanup precision, cost and production flexibility, required water depth for operation, ability to access the site, and compatibility with disposal options.

Palermo, M.R.; Pankow, V.R.

1988-11-01

12

Estuaries  

NSDL National Science Digital Library

An estuary is a body of water that is created when freshwater from rivers and streams flows into the saltwater of an ocean. To understand this mixing of fresh and salt water, learners go through several activities: 1) in Salt and Water, learners dissolve salt crystals in water to observe their effects on water; 2) in Making a Salt Wedge, learners make a model of a salt wedge estuary, which occurs in nature when the mouth of a river flows directly into seawater; 3) in Plant Dehydration learners observe the effects of salinity (salt content in the water) on live plants. Includes a wrap-up guide for group discussions.

Jersey, New; Center, Liberty S.; Coalition, New J.

2006-01-01

13

Restoration of Hydrodynamic and Hydrologic Processes in the Chinook River Estuary, Washington – Feasibility Assessment  

SciTech Connect

A hydrodynamic and hydrologic modeling analysis was conducted to evaluate the feasibility of restoring natural estuarine functions and tidal marine wetlands habitat in the Chinook River estuary, located near the mouth of the Columbia River in Washington. The reduction in salmonid populations is attributable primarily to the construction of a Highway 101 overpass across the mouth of the Chinook River in the early 1920s with a tide gate under the overpass. This construction, which was designed to eliminate tidal action in the estuary, has impeded the upstream passage of salmonids. The goal of the Chinook River Restoration Project is to restore tidal functions through the estuary, by removing the tide gate at the mouth of the river, filling drainage ditches, restoring tidal swales, and reforesting riparian areas. The hydrologic model (HEC-HMS) was used to compute Chinook River and tributary inflows for use as input to the hydrodynamic model at the project area boundary. The hydrodynamic model (RMA-10) was used to generate information on water levels, velocities, salinity, and inundation during both normal tides and 100-year storm conditions under existing conditions and under the restoration alternatives. The RMA-10 model was extended well upstream of the normal tidal flats into the watershed domain to correctly simulate flooding and drainage with tidal effects included, using the wetting and drying schemes. The major conclusion of the hydrologic and hydrodynamic modeling study was that restoration of the tidal functions in the Chinook River estuary would be feasible through opening or removal of the tide gate. Implementation of the preferred alternative (removal of the tide gate, restoration of the channel under Hwy 101 to a 200-foot width, and construction of an internal levee inside the project area) would provide the required restorations benefits (inundation, habitat, velocities, and salinity penetration, etc.) and meet flood protection requirements. The alternative design included design of storage such that relatively little difference in the drainage or inundation upstream of Chinook River Valley Road would occur as a result of the proposed restoration activities.

Khangaonkar, Tarang P.; Breithaupt, Stephen A.; Kristanovich, Felix C.

2006-08-03

14

Restoration of Hydrodynamic and Hydrologic Processes in the Chinook River Estuary, Washington – Feasibility Assessment  

SciTech Connect

A hydrodynamic and hydrologic modeling analysis was conducted to evaluate the feasibility of restoring natural estuarine functions and tidal marine wetlands habitat in the Chinook River estuary, located near the mouth of the Columbia River in Washington. The reduction in salmonid populations is attributable primarily to the construction of a Highway 101 overpass across the mouth of the Chinook River in the early 1920s with a tide gate under the overpass. This construction, which was designed to eliminate tidal action in the estuary, has impeded the upstream passage of salmonids. The goal of the Chinook River Restoration Project is to restore tidal functions through the estuary, by removing the tide gate at the mouth of the river, filling drainage ditches, restoring tidal swales, and reforesting riparian areas. The hydrologic model (HEC-HMS) was used to compute Chinook River and tributary inflows for use as input to the hydrodynamic model at the project area boundary. The hydrodynamic model (RMA-10) was used to generate information on water levels, velocities, salinity, and inundation during both normal tides and 100-year storm conditions under existing conditions and under the restoration alternatives. The RMA-10 model was extended well upstream of the normal tidal flats into the watershed domain to correctly simulate flooding anddrainage with tidal effects included, using the wetting and drying schemes. The major conclusion of the hydrologic and hydrodynamic modeling study was that restoration of the tidal functions in the Chinook River estuary would be feasible through opening or removal of the tide gate. Implementation of the preferred alternative (removal of the tide gate, restoration of the channel under Hwy 101 to a 200-foot width, and construction of an internal levee inside the project area) would provide the required restorations benefits (inundation, habitat, velocities, and salinity penetration, etc.) and meet flood protection requirements. The alternative design included design of storage such that relatively little difference in the drainage or inundation upstream of Chinook River Valley Road would occur as a result of the proposed restoration activities.

Khangaonkar, Tarang P.; Breithaupt, Stephen A.; Kristanovich, Felix C.

2006-01-01

15

Feasibility study for convertible engine torque converter  

NASA Technical Reports Server (NTRS)

The feasibility study has shown that a dump/fill type torque converter has excellent potential for the convertible fan/shaft engine. The torque converter space requirement permits internal housing within the normal flow path of a turbofan engine at acceptable engine weight. The unit permits operating the engine in the turboshaft mode by decoupling the fan. To convert to turbofan mode, the torque converter overdrive capability bring the fan speed up to the power turbine speed to permit engagement of a mechanical lockup device when the shaft speed are synchronized. The conversion to turbofan mode can be made without drop of power turbine speed in less than 10 sec. Total thrust delivered to the aircraft by the proprotor, fan, and engine during tansient can be controlled to prevent loss of air speed or altitude. Heat rejection to the oil is low, and additional oil cooling capacity is not required. The turbofan engine aerodynamic design is basically uncompromised by convertibility and allows proper fan design for quiet and efficient cruise operation. Although the results of the feasibility study are exceedingly encouraging, it must be noted that they are based on extrapolation of limited existing data on torque converters. A component test program with three trial torque converter designs and concurrent computer modeling for fluid flow, stress, and dynamics, updated with test results from each unit, is recommended.

1985-01-01

16

Measuring the contribution of benthic ecosystem engineering species to the ecosystem services of an estuary: A case study of burrowing shrimps in Yaquina Estuary, Oregon  

EPA Science Inventory

Burrowing shrimps are regarded as ecosystem engineering species in many coastal ecosystems worldwide, including numerous estuaries of the west coast of North America (Baja California to British Columbia). In estuaries of the U.S. Pacific Northwest, two species of large burrowing...

17

Measuring the contribution of benthic ecosystem engineering species to the ecosystem services of an estuary: A case study of burrowing shrimps in Yaquina Estuary, Oregon - April 2009  

EPA Science Inventory

Burrowing shrimps are regarded as ecosystem engineering species in many coastal ecosystems worldwide, including numerous estuaries of the west coast of North America (Baja California to British Columbia). In estuaries of the U.S. Pacific Northwest, two species of large burrowing...

18

Engineering aspects of site-specific oil spill contingency planning for estuaries  

E-print Network

ENGINEERING ASPECTS OF SITE-SPECIFIC OIL SPILL CONTINGENCY PLANNING FOR ESTUARIES A Thesis by DAVID WOODY JAMES Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1984 Major Subject: Civil Engineering ENGINEERING ASPECTS OP SITE-SPECIFIC OIL SPILL CONTINGENCY PLANNING FOR ESTDARIES A Thesis by DAVID WOODY JAMES Approved as to style and content by: Dr. Ro W. Bann, Jr. (Chairman of Committee) Dr...

James, David Woody

2012-06-07

19

Civil Engineering Feasibility Studies for Future Ring Colliders at CERN  

E-print Network

CERN civil engineers are studying the feasibility of several potential ring colliders to complement the LHC: an 80km circular tunnel to house the TLEP and VHE-LHC, and the ring-ring and linac-ring options for the LHeC. The feasibility of these projects is largely dependent on civil design and geotechnical and environmental risks. As civil infrastructure works typically represent one third of the cost of major physics projects, it is critical that the construction costs are well understood from the conceptual stage. This proceeding presents the first results of the feasibility studies for the 80km tunnel and the linac-ring LHeC. Presented at IPAC'13 Shanghai, 12-17 May 2013

Bruning, O; Myers, S; Osborne, J; Rossi, L; Waaijer, C; Zimmermann, F

2013-01-01

20

Engineer reconnaissance with a video camera: feasibility study  

E-print Network

campaign from Field Marshal Montgomery's failed seizure of a "bridge too far" in Arnheim, Holland to the Soviet Union's unique use of ice bridges to resupply the defenders of Stalingrad. From a military standpoint, bridges either exist or need... OBJECTIVES This study will evaluate the feasibility of the acquisition of remote sensed engineer reconnaissance data (through the use of a Charged-Coupled Device !CCD) video camera, laser rangefinder and angle measuring capability) and subsequent...

Bergner, Kirk Michael

2012-06-07

21

Managing Nutrients in two New England Estuaries: The Feasibility of Using Stable Isotopes to Monitor Nitrate Sources  

Microsoft Academic Search

Nitrogen is the limiting nutrient in many estuaries, and the rising availability of nitrogen has led to increased eutrophication in many coastal ecosystems. In order to reduce nitrogen loading to coastal waters it is necessary to know the relative importance of the various sources, both point and non-point. Recent studies have shown that sources of nitrate, the most bioavailable form

R. T. Barnes; G. Benoit; S. Anisfeld

2004-01-01

22

Will the balance of power shift among native eastern Pacific estuary ecosystem engineers with the introduced bopyrid isopod parasite orthione griffenis?  

EPA Science Inventory

The blue mud shrimp, Upogebia pugettensis, the bay ghost shrimp, Neotrypaea californiensis, and eelgrass, Zostera marina are endemic ecosystem engineers that define the ecological structure and function of estuaries along the Pacific coast of the US as significantly as do marshes...

23

Exoskeletal Engine Concept: Feasibility Studies for Medium and Small Thrust Engines  

NASA Technical Reports Server (NTRS)

The exoskeletal engine concept is one in which the shafts and disks are eliminated and are replaced by rotating casings that support the blades in spanwise compression. Omission of the shafts and disks leads to an open channel at the engine centerline. This has immense potential for reduced jet noise and for the accommodation of an alternative form of thruster for use in a combined cycle. The use of ceramic composite materials has the potential for significantly reduced weight as well as higher working temperatures without cooling air. The exoskeletal configuration is also a natural stepping-stone to complete counter-rotating turbomachinery. Ultimately this will lead to reductions in weight, length, parts count and improved efficiency. The feasibility studies are in three parts. Part 1: Systems and Component Requirements addressed the mechanical aspects of components from a functionality perspective. This effort laid the groundwork for preliminary design studies. Although important, it is not felt to be particularly original, and has therefore not been included in the current overview. Part 2: Preliminary Design Studies turned to some of the cycle and performance issues inherent in an exoskeletal configuration and some initial attempts at preliminary design of turbomachinery were described. Twin-spoon and single-spool 25,800-lbf-thrust turbofans were used as reference vehicles in a mid-size commercial subsonic category in addition to a single-spool 5,000-lbf-thrust turbofan that represented a general aviation application. The exoskeletal engine, with its open centerline, has tremendous potential for noise suppression and some preliminary analysis was done which began to quantify the benefits. Part 3: Additional Preliminary Design Studies revisited the design of single-spool 25,800-lbf-thrust turbofan configurations, but in addition to the original FPR = 1.6 and BPR = 5.1 reference engine. two additional configurations used FPR = 2.4 and BPR = 3.0 and FPR = 3.2 and BPR = 2.0 were investigated. The single-spool 5.000-lbf-thrust turbofan was refined and the small engine study was extended to include a 2,000-lbf-thrust turbojet. More attention was paid to optimizing the turbomachinery. Turbine cooling flows were eliminated, in keeping with the use of uncooled CMC materials in exoskeletal engines. The turbine performance parameters moved much closer to the nominal target values, demonstrating the great benefits to the cycle of uncooled turbines.

Halliwell, Ian

2001-01-01

24

Exoskeletal Engine Concept: Feasibility Studies for Medium and Small Thrust Engines  

NASA Technical Reports Server (NTRS)

The exoskeletal engine concept is one in which the shafts and disks are eliminated and are replaced by rotating casings that support the blades in spanwise compression. Omission of the shafts and disks leads to an open channel at the engine centerline. This has immense potential for reduced jet noise and for the accomodation of an alternative form of thruster for use in a combined cycle. The use of ceramic composite materials has the potential for significantly reduced weight as well as higher working temperatures without cooling air. The exoskeletal configuration is also a natural stepping-stone to complete counter-rotating turbomachinery. Ultimately this will lead to reductions in weight, length, parts count and improved efficiency. The feasibility studies are in three parts. Part I-Systems and Component Requirements addressed the mechanical aspects of components from a functionality perspective. This effort laid the groundwork for preliminary design studies. Although important, it is not felt to be particularly original, and has therefore not been included in the current overview. Part 2-Preliminary Design Studies turned to some of the cycle and performance issues inherent in an exoskeletal configuration and some initial attempts at preliminary design of turbomachinery were described. Twin-spoon and single-spool 25.800-lbf-thrust turbofans were used as reference vehicles in a mid-size commercial subsonic category in addition to a single-spool 5,000-lbf-thrust turbofan that represented a general aviation application. The exoskeletal engine, with its open centerline, has tremendous potential for noise suppression and some preliminary analysis was done which began to quantify the benefits. Part 3-Additional Preliminary Design Studies revisited the design of single-spool 25,800-lbf-thrust turbofan configurations, but in addition to the original FPR = 1.6 and BPR = 5.1 reference engine, two additional configurations used FPR = 2.4 and BPR = 3.0 and FPR = 3.2 and BPR = 2.0 were investigated. The single-spool 5,000-lbf-thrust turbofan was refined and the small engine study was extended to include a 2,000-lbf-thrust turbojet. More attention was paid to optimizing the turbomachinery. Turbine cooling flows were eliminated, in keeping with the use of uncooled CMC material in exoskeletal engines. The turbine performance parameters moved much closer to the nominal target values, demonstrating the great benefits to the cycle of uncooled turbines.

Halliwell, Ian

2001-01-01

25

A feasibility study of a new ATREX engine system of aft-turbine configuration  

Microsoft Academic Search

A feasibility of ATREX (Air-Turbo-Ram Expander cycle) engine with conventional aft-turbine configuration has been studied to be developed in about 10 years, if the development project has started under enough resources. The novel tip-turbine of the original ATREX engine is replaced by a conventional aft-turbine, and the maximum turbine inlet temperature (TTT) is reduced to 1200K, to realize the engine

Nobuhiro Tanatsugu; T. Sato; H. Kobayashi

2002-01-01

26

Reverse Engineering Time Discrete Finite Dynamical Systems: A Feasible Undertaking?  

PubMed Central

With the advent of high-throughput profiling methods, interest in reverse engineering the structure and dynamics of biochemical networks is high. Recently an algorithm for reverse engineering of biochemical networks was developed by Laubenbacher and Stigler. It is a top-down approach using time discrete dynamical systems. One of its key steps includes the choice of a term order, a technicality imposed by the use of Gröbner-bases calculations. The aim of this paper is to identify minimal requirements on data sets to be used with this algorithm and to characterize optimal data sets. We found minimal requirements on a data set based on how many terms the functions to be reverse engineered display. Furthermore, we identified optimal data sets, which we characterized using a geometric property called “general position”. Moreover, we developed a constructive method to generate optimal data sets, provided a codimensional condition is fulfilled. In addition, we present a generalization of their algorithm that does not depend on the choice of a term order. For this method we derived a formula for the probability of finding the correct model, provided the data set used is optimal. We analyzed the asymptotic behavior of the probability formula for a growing number of variables n (i.e. interacting chemicals). Unfortunately, this formula converges to zero as fast as , where and . Therefore, even if an optimal data set is used and the restrictions in using term orders are overcome, the reverse engineering problem remains unfeasible, unless prodigious amounts of data are available. Such large data sets are experimentally impossible to generate with today's technologies. PMID:19295916

Delgado-Eckert, Edgar

2009-01-01

27

Engineering feasibility of in-situ subsurface isolation barriers  

SciTech Connect

In the remediation of radioactive waste disposal sites there are occasional situations where it is not feasible to remove the waste or contaminated soil and a containment approach is more appropriate. This paper is a discussion of a DOE funded research and development study [1] on the feasibility of in situ construction bottom barrier containment structures in soil under and around large contaminated sites. The evaluated bottom barrier method begins with a conventional slurry trench around the perimeter of a site. The method utilizes high-density slurry grout and a cable saw mechanism to make a controlled horizontal cut at the base of the slurry trench. Gravity alone forces the dense slurry into the horizontal cut and causes the entire block of earth to literally float in a slurry grout that cures into an impermeable barrier material. The work included evaluation of a completed field test that floated a 50-ton block of earth, development of a computer model of the process, evaluation of structural hydraulic and shearing forces on the earth block, measurement of friction and cutting forces in a field test, hardware design drawings, cost analysis, and an ASME review. The study evaluated issues such as scalability, and adaptability to various geologic conditions such as soil types and layers, hills, rocks, saturated soil, faults, waste density variations, fractures and unconsolidated soil formations. A method to measure the integrity of the barrier both after construction and periodically in the future was also evaluated. Barrier durability, erosion, bio-penetration, and moisture related cracking, and response to earth movements is also considered. Reactive and adsorptive chemistry to relatively thick layers of barrier material are proposed that may further improve long term containment. (authors)

Carter, E.E. [Carter Technologies Co, Sugar Land, TX (United States)

2007-07-01

28

Session 6: Magma Energy: Engineering Feasibility of Energy Extraction from Magma Bodies  

Microsoft Academic Search

Extensive quantities of high-quality energy are estimated to be available from molten magma bodies existing within 10 Km of the US continent's surface. A five-year study sponsored by DOE\\/BES demonstrated that extraction of energy from these melts was scientifically feasible. The next stage of assessment is to evaluate the engineering feasibility of energy extraction and provide a preliminary economic evaluation.

Traeger

1983-01-01

29

Geo-feasibility of in situ sediment capping in a Great Lakes urban estuary: a sediment budget assessment  

NASA Astrophysics Data System (ADS)

Presque Isle Bay is one of 40 remaining environmental areas of concern (AoCs) on the North American Great Lakes that have one or more water, habitat, or sediment quality impairments as defined by the International Joint Commission. In situ natural capping using sediment from to-be-remediated watersheds and other potential sources is being considered as the most feasible means of remediating an existing contaminated sediment problem at this site. A multi-decade (˜40 year) sediment budget shows that, when localized anthropogenic effects (dredging, reclamation) are discounted, the bay net-accumulated sediment over time. Sediment was supplied from three major sources: bank erosion and bluff retreat (41%), streams (25%), and the Lake Erie littoral system (20%). The non-stream sources supply environmentally clean materials from ancient beach and glacio-lacustrine deposits along the shoreline, and from the modern littoral system. Organic and metallic contaminants supplied primarily by streams and run-off remain a remediation challenge for the AoC. Geologically, natural capping of contaminants over the next several decades is a viable solution for most of the bay. The mechanism may not work effectively in all areas because approximately 25% of the bay floor is moderately net-erosional while several localized areas accumulate sediments very slowly at decadal timescales.

Foyle, Anthony M.; Norton, Kevin P.

2007-10-01

30

Krypton-85 hydrofracture engineering feasibility and safety evaluation  

SciTech Connect

Engineering studies have been made to determine the hazards associated with the disposal of /sup 85/Kr using the hydrofracture process. To assess the hazards, an effort has been made to identify the equipment required to entrain and dissolve the noble gas into the grout stream at hydrofracture pressure (up to 350 bar). Off-the-shelf or slightly modified equipment has been identified for safe and effective compression and gas-grout mixing. Each monthly injection disposes of 1.6 x 10/sup 6/ Ci of /sup 85/Kr. By connecting only one gas cylinder to the injection system at a time, the maximum amount of krypton likely to be released as a result of equipment failure is limited to 128,000 Ci. An evaluation by Los Alamos Technical Associates shows that releasing this amount of gas in less than one hour under worst-case meteorological conditions through a 30-m stack would result in a whole-body dose of 170 millirem at a distance of 1 km from the facility. A krypton collection and recovery system can further reduce this dose to 17 millirem; increasing the distance to the site boundary to 3 km can also reduce the dose by a factor of ten. Lung and skin dose estimates are 1.6 and 120 times the whole-body dose, respectively. These are all worst-case values; releases under more typical conditions would result in a significantly lower dose. No insurmountable safety or engineering problems have been identified.

Peretz, F.J.; Muller, M.E.; Pan, P.Y.

1981-07-01

31

Energy efficiency and economic feasibility of CCHP driven by stirling engine  

Microsoft Academic Search

This paper deals with the problem of energy efficiency evaluation and economic feasibility analysis of a small scale trigeneration system for combined cooling, heating and power generation (CCHP) with an available Stirling engine. Trigeneration systems have a large potential of energy saving and economical efficiency. The decisive values for energetic efficiency evaluation of such systems are the primary energy rate

X. Q. Kong; R. Z. Wang; X. H. Huang

2004-01-01

32

Converting an estuary to Lake Grevelingen: Environmental review of a coastal engineering project  

NASA Astrophysics Data System (ADS)

To guarantee protection from storm floods in the southwestern part of the Netherlands, the length of exposed coastline is being greatly reduced by the construction of dams and a storm surge barrier. As part of the Delta Project, the mouth of the Grevelingen estuary was closed in 1971. Due to the closure, tidal movement was eliminated, which resulted in changes in environmental factors such as transparency and chloride and phosphate concentration. The number of plant and animal groups decreased. Large areas of sand flats and salt marshes, which were formerly exposed to the tides, were left “high and dry.” This resulted in enormous changes for the communities living in these areas. The development of a new ecological system and the changed potential afforded by the water and land areas for human use, emphasized the need for physical planning. The potential uses (functions) of the new system are discussed in this article. Special attention is given to the demand for recreational facilities and nature conservation and to the balanced realization of these main functions. The methods applied in choosing between alternatives in physical planning are explained. Water quality and ecosystem management are discussed. One of the main management objectives is the prevention of a further decrease in the chloride concentration and the number of species. A sluice was, therefore, put into operation in 1978, by means of which water was exchanged between the North Sea and Lake Grevelingen. The responses observed are discussed here. In the near future, a crucial decision will have to be made: Will Lake Grevelingen remain a salt-water lake or will it become a fresh-water lake?

Saeijs, H. L. F.; Stortelder, P. B. M.

1982-09-01

33

Exploring Estuaries  

NSDL National Science Digital Library

Exploring Estuaries introduces students of various ages to the ecology of estuaries, places where freshwater rivers and streams flow into the ocean, mixing with the seawater. It is part of a broader effort by the National Estuary Program to educate the general public about estuaries and to restore and protect these sensitive ecosystems. It offers interactive games and activities as well as virtual tours of Long Island Sound and the Barataria-Terrebonne Estuarine Complex near New Orleans. A glossary page defines technical terms used throughout the site. Resources also are provided for teachers and students interested in learning more about related organizations, publications, and websites.

34

A feasibility study of a new ATREX engine system of aft-turbine configuration  

NASA Astrophysics Data System (ADS)

A feasibility of ATREX (Air-Turbo-Ram Expander cycle) engine with conventional aft-turbine configuration has been studied to be developed in about 10 years, if the development project has started under enough resources. The novel tip-turbine of the original ATREX engine is replaced by a conventional aft-turbine, and the maximum turbine inlet temperature (TTT) is reduced to 1200K, to realize the engine by only using approved metal technologies of modern jet engines. The capability of the performance has been shown by parametric studies by changing components' design parameters. The study shows that the performance of the ATREX engine is not less than that of pre-cooled turbo jet. Some technical issues on developing the new ATREX engine have been addressed. The most important issue would come from the transient total temperature change due to the rapid acceleration from sea level static (SLS) condition (288K) to Mach 6 at 30km of altitude (1680K) in 6 minutes. The deformation due to transient thermal expansion has to be controlled. Especially, the change of the tip clearance and the clearance between rotors and stators are pointed out to be important design issues. The ATREX engine, which has shorter axial length and simpler rotor, has structural advantage over turbo jet.

Isomura, Kousuke; Omi, Junsuke; Tanatsugu, Nobuhiro; Sato, Tetsuya; Kobayashi, Hiroaki

2002-07-01

35

Engine Company Evaluation of Feasibility of Aircraft Retrofit Water-Injected Turbomachines  

NASA Technical Reports Server (NTRS)

This study supports the NASA Glenn Research Center and the U.S. Air Force Research Laboratory in their efforts to evaluate the effect of water injection on aircraft engine performance and emissions. In this study, water is only injected during the takeoff and initial climb phase of a flight. There is no water injection during engine start or ground operations, nor during climb, cruise, descent, or landing. This study determined the maintenance benefit of water injection during takeoff and initial climb and evaluated the feasibility of retrofitting a current production engine, the PW4062 (Pratt & Whitney, East Hartford, CT), with a water injection system. Predicted NO(x) emissions based on a 1:1 water-tofuel ratio are likely to be reduced between 30 to 60 percent in Environmental Protection Agency parameter (EPAP). The maintenance cost benefit for an idealized combustor water injection system installed on a PW4062 engine in a Boeing 747-400ER aircraft (The Boeing Company, Chicago, IL) is computed to be $22 per engine flight hour (EFH). Adding water injection as a retrofit kit would cost up to $375,000 per engine because of the required modifications to the fuel system and addition of the water supply system. There would also be significant nonrecurring costs associated with the development and certification of the system that may drive the system price beyond affordability.

Becker, Arthur

2006-01-01

36

Feasibility of Biomarker Studies for Engineered Nanoparticles: What Can Be Learned from Air Pollution Research  

PubMed Central

Objective Occupational exposure to engineered nanoparticles (NP) may pose health risks to the workers. This article is to discuss the feasibility of identifying biomarkers that are associated with NP exposure. Methods Scientific literature on the adverse health effects of ambient ultrafine particles (UFP) and NP was reviewed to discuss the feasibility of conducting biomarker studies to identify NP-induced early biological changes. Results Various approaches for biomarker studies have been identified, including potential injury pathways that need to be considered and the methodologies that may be used for such studies. Conclusions Although NP may have novel mechanisms of injury, much can be learned from our experience in studying UFP. Oxidative stress-related pathways could be an important consideration for identifying NP-associated biomarkers and one of the most effective approaches for such studies may be proteome profiling. PMID:21654422

Li, Ning; Nel, Andre E.

2011-01-01

37

The electrochemical reduction of carbon dioxide to formate/formic acid: engineering and economic feasibility.  

PubMed

The engineering and economic feasibility of large-scale electrochemical reduction of carbon dioxide to formate salts and formic acid is the focus of this Full Paper. In our study we investigated the long-term performance of tin and other proprietary catalysts in the reduction of carbon dioxide to formate/formic acid at a gas/solid/liquid interface, using a flow-through reactor. The overall economics and energy consumption of the process are evaluated through a value chain analysis. The sensitivity of the net present value of the process to various process parameters is examined. PMID:21922681

Agarwal, Arun S; Zhai, Yumei; Hill, Davion; Sridhar, Narasi

2011-09-19

38

Idaho Nuclear Technology and Engineering Center Newly Generated Liquid Waste Demonstration Project Feasibility Study  

SciTech Connect

A research, development, and demonstration project for the grouting of newly generated liquid waste (NGLW) at the Idaho Nuclear Technology and Engineering Center is considered feasible. NGLW is expected from process equipment waste, decontamination waste, analytical laboratory waste, fuel storage basin waste water, and high-level liquid waste evaporator condensate. The potential grouted waste would be classed as mixed low-level waste, stabilized and immobilized to meet RCRA LDR disposal in a grouting process in the CPP-604 facility, and then transported to the state.

Herbst, A.K.

2000-02-01

39

A hingeless rotor XV-15 design integration feasibility study. Volume 1: Engineering design studies  

NASA Technical Reports Server (NTRS)

A design integration feasibility study was carried out to investigate what modifications to the basic XV-15 were necessary to accomplish a flight demonstration of the XV-15 with a Boeing hingeless rotor. Also investigated were additional modifications which would exploit the full capability provided by the combination of the new rotor and the existing T53 engine. An evaluation of the aircraft is presented and the data indicate improved air vehicle performance, acceptable aeroelastic margins, lower noise levels and improved flying qualities compared with the XV-15 aircraft. Inspection of the rotor system data provided shows an essentially unlimited life rotor for the flight spectrum anticipated for the XV-15.

Magee, J. P.; Alexander, H. R.

1978-01-01

40

Feasibility Investigation on the Development of a Structural Damage Diagnostic and Monitoring System for Rocket Engines  

NASA Technical Reports Server (NTRS)

The research activity for this project is mainly to investigate the necessity and feasibility to develop a structural health monitoring system for rocket engines, and to carry out a research plan for further development of the system. More than one hundred technical papers have been searched and reviewed during the period. We concluded after this investigation that adding a new module in NASA's existing automated diagnostic system to monitor the healthy condition of rocket engine structures is a crucial task, and it's possible to develop such a system based upon the vibrational-based nondestructive damage assessment techniques. A number of such techniques have been introduced. Their advantages and disadvantages are also discussed. A global research plan has been figured out. As the first step of the overall research plan, a proposal for the next fiscal year has been submitted.

Shen, Ji Y.; Sharpe, Lonnie, Jr.

1998-01-01

41

Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME  

Microsoft Academic Search

The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control

John Pratapas; Daniel Mather; Anton Kozlovsky

2007-01-01

42

Estuary Live!!!  

NSDL National Science Digital Library

Intended for elementary, middle, and high school students, this electronic estuary excursion, Estuary Live!!!, will take place May 8-12, 2000. Free to participants (but please sign up in advance), the field trip will explore the Rachel Carson Site of the North Carolina National Estuarine Research Reserve, covering four islands and salt marshes off the North Carolina coast. The site features useful educational materials, including a photo-illustrated field guide (of the "ecology, habitats and specific plants and animals found in North Carolina's estuaries"); lesson plans (covering highschool biology, estuary habitats, species interactions, and adaptations and communities); and a series of related links. The interactive field trip will require a java-enabled browser, RealVideo (to see a moving image and hear sound), and/or Chatvideo, to see a moving image, ask questions of the naturalist leading the trip, and receive responses via a chat window. Note that ChatVideo requires Netscape 4.0 or better and will not work with AOL or Internet Explorer, and pages "look best" on a screen with resolution of 800x600. The Estuary Live!!! Website is provided by the North Carolina National Estuarine Research Reserve Program, and The Center for Science, Mathematics and Technology Education at East Carolina University.

43

Exploring Estuaries  

NSDL National Science Digital Library

This site offers several ways to explore the importance of estuaries. Virtual tours of the Barataria-Terrebone Estuarine Complex and the Long Island Sound offer photos and text of each area explain their importance to humans, wildlife, and larger ecosystems. Additional resources for kids and adults are linked. A glossary page offers a list of vocabulary associated with estuaries. The site also offers a games and activities section for kids that has coloring sheets for young children, and inquiry-based interactive games for older kids. The games include a "Who Am I" animal identification game, and a game called "Solve a Mystery" where players must follow and investigation into what's wrong with an estuary, and make a decision on the cause of the problem. There are several possible mysteries to solve, each with a different solution.

44

Conceptual Design and Feasibility of Foil Bearings for Rotorcraft Engines: Hot Core Bearings  

NASA Technical Reports Server (NTRS)

Recent developments in gas foil bearing technology have led to numerous advanced high-speed rotating system concepts, many of which have become either commercial products or experimental test articles. Examples include oil-free microturbines, motors, generators and turbochargers. The driving forces for integrating gas foil bearings into these high-speed systems are the benefits promised by removing the oil lubrication system. Elimination of the oil system leads to reduced emissions, increased reliability, and decreased maintenance costs. Another benefit is reduced power plant weight. For rotorcraft applications, this would be a major advantage, as every pound removed from the propulsion system results in a payload benefit.. Implementing foil gas bearings throughout a rotorcraft gas turbine engine is an important long-term goal that requires overcoming numerous technological hurdles. Adequate thrust bearing load capacity and potentially large gearbox applied radial loads are among them. However, by replacing the turbine end, or hot section, rolling element bearing with a gas foil bearing many of the above benefits can be realized. To this end, engine manufacturers are beginning to explore the possibilities of hot section gas foil bearings in propulsion engines. This overview presents a logical follow-on activity by analyzing a conceptual rotorcraft engine to determine the feasibility of a foil bearing supported core. Using a combination of rotordynamic analyses and a load capacity model, it is shown to be reasonable to consider a gas foil bearing core section. In addition, system level foil bearing testing capabilities at NASA Glenn Research Center are presented along with analysis work being conducted under NRA Cooperative Agreements.

Howard, Samuel A.

2007-01-01

45

Feasibility Demonstration of a 445N High-Performance Rocket Engine  

NASA Technical Reports Server (NTRS)

A program to demonstrate the feasibility of a high-performance 445 Newton (100 lb(sub f)) NTO/NMH rocket engine is presented. An existing high-performance injector was coupled with three different thrust chambers to acquire test data for the program. A stainless-steel sea-level chamber was used for test stand checkout, calibration and initial injector performance determinations. Two high-temperature iridium lined rhenium thrust chambers were used to determine altitude performance and durability. The first chamber was tested for a total duration of 3381 s and the second was tested for a total duration of 15,000 s with no measurable degradation. Extrapolation of epsilon = 44:1 experimental data to the recommended epsilon = 467:1 expansion nozzle, using the JANNAF methodology, showed that a performance of 3138 to 3167 N-s/kg (320 to 323 lb(sub f-s)/lb(sub m) could be achieved with the present design. Recommendations are presented which would allow a redesigned engine to achieve the 3195 N-s/kg (326 lb(sub f-s)/lb(sub m)) program goal.

Appel, Marshall A.; Schoenman, Leonard; Franklin, Jerrold E.; Lansaw, P. Tina

1989-01-01

46

Classification of Estuaries  

NSDL National Science Digital Library

This text states that although all estuaries are similar in that they are semi-enclosed bodies of brackish water, they are categorized with regard to geological characteristics, and further distinguished on the basis of stratification and circulation patterns. According to their geological characteristics, estuaries are classified as: drowned river valleys or coastal-plain estuaries, bar-built estuaries or lagoons, fjord-type estuaries, and tectonically caused estuaries. Each type is explained in detail and examples are given for each.

47

Classification of Estuaries  

NSDL National Science Digital Library

This text states that although all estuaries are similar in that they are semi-enclosed bodies of brackish water, they are categorized with regard to geological characteristics, and further distinguished on the basis of stratification and circulation patterns. According to their geological characteristics, estuaries are classified as: drowned river valleys or coastal-plain estuaries, bar-built estuaries or lagoons, fjord-type estuaries, and tectonically caused estuaries. Each type is explained in detail and examples are given for each.

Oberrecht, Kenn

2007-01-30

48

IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 15, NO. 1, MARCH 2007 23 Technical Feasibility of Teleassessments  

E-print Network

IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 15, NO. 1, MARCH 2007 23, and Samantha Weinstein Abstract--Background: technical feasibility was evaluated for conducting standard motor in the formative stage with a growing body of research but with little impact to date on clinical practice

Durfee, William K.

49

Estuaries: Finding the Balance  

NSDL National Science Digital Library

Students can use this resource from the National Geographic to examine the conflict between development and the environment by focusing on estuaries across the United States. Its objectives are for students to learn about the environmental and economic importance of estuaries, consider the conflicts that arise because of the many uses of estuaries, research a specific estuary and the problems and solutions that have developed around it, and suggest compromises that might be made in order to protect both estuaries and economic development. To meet these objectives, students are directed to review a number of websites about estuaries and then to answer questions concerning environmental issues (e.g., What are the specific ecological characteristics of estuaries? What are some of the signs that an estuary is in trouble as a habitat?) and economic issues (e.g., How might proximity to major cities impact estuaries? To what degree should economic activity dictate the outcome of estuaries?).

Xpeditions NatGeo (National Geographic Society;)

2008-04-30

50

Embedded Acoustic Sensor Array for Engine Fan Noise Source Diagnostic Test: Feasibility of Noise Telemetry via Wireless Smart Sensors  

NASA Technical Reports Server (NTRS)

Aircraft engines have evolved into a highly complex system to meet ever-increasing demands. The evolution of engine technologies has primarily been driven by fuel efficiency, reliability, as well as engine noise concerns. One of the sources of engine noise is pressure fluctuations that are induced on the stator vanes. These local pressure fluctuations, once produced, propagate and coalesce with the pressure waves originating elsewhere on the stator to form a spinning pressure pattern. Depending on the duct geometry, air flow, and frequency of fluctuations, these spinning pressure patterns are self-sustaining and result in noise which eventually radiate to the far-field from engine. To investigate the nature of vane pressure fluctuations and the resulting engine noise, unsteady pressure signatures from an array of embedded acoustic sensors are recorded as a part of vane noise source diagnostics. Output time signatures from these sensors are routed to a control and data processing station adding complexity to the system and cable loss to the measured signal. "Smart" wireless sensors have data processing capability at the sensor locations which further increases the potential of wireless sensors. Smart sensors can process measured data locally and transmit only the important information through wireless communication. The aim of this wireless noise telemetry task was to demonstrate a single acoustic sensor wireless link for unsteady pressure measurement, and thus, establish the feasibility of distributed smart sensors scheme for aircraft engine vane surface unsteady pressure data transmission and characterization.

Zaman, Afroz; Bauch, Matthew; Raible, Daniel

2011-01-01

51

The study of the feasibility of segmental bone defect repair with tissue- engineered bone membrane: a qualitative observation  

PubMed Central

The objective of the study was to investigate the feasibility of intramembranous osteogenesis from tissue-engineered bone membrane in vivo. Bone marrow mesenchymal stem cells (MSCs) of rabbits were harvested, expanded and some of them were induced into osteoblasts. Porcine small intestinal submucosa (SIS) was converted by a series of physical and chemical procedures into a scaffold. MSCs and induced osteoblasts were seeded separately onto the scaffold, thus fabricating two kinds of tissue-engineered bone membrane. A total of 12 New Zealand rabbits were subjected to a surgical operation; a 15 mm bone segment, including the periosteum, was resected from the radius on both sides of each rabbit to create critical bone defects. The two kinds of tissue-engineered bone membrane and SIS (as control) were implanted randomly into the site of bone defect. The animals had radiographs and were killed after 4 weeks. The specimens were harvested and histological examination performed for evidence of osteogenesis. Bone tissue had formed in defects treated by the two kinds of tissue-engineered bone membrane at 4 weeks. This was supported by the X-ray and histological examination, which confirmed the segmental gap bridged by bone. There was no attempt to bridge in the bone defect treated by SIS. Tissue-engineered bone membrane, constructed by seeding allogeneic cells on an xenogeneic and bio-derived scaffold, can repair critical bone defects successfully. PMID:18427729

Zhao, Jun-Li; Wan, Lin; Wang, Shuan-Ke

2008-01-01

52

CF6 jet engine performance improvement program. Task 1: Feasibility analysis  

NASA Technical Reports Server (NTRS)

Technical and economic engine improvement concepts selected for subsequent development include: (1) fan improvement; (2) short core exhaust; (3) HP turbine aerodynamic improvement; (4) HP turbine roundness control; (5) HP turbine active clearance control; and (6) cabin air recirculation. The fuel savings for the selected engine modification concepts for the CF6 fleet are estimated.

Fasching, W. A.

1979-01-01

53

rRNA (rrn) Operon-Engineered Bacillus subtilis as a Feasible Test Organism for Antibiotic Discovery  

PubMed Central

Bacillus subtilis contains 10 rRNA (rrn) operons. We found that rRNA operon-engineered B. subtilis strain RIK543, with only the rrnO operon, is specifically hypersensitive to RNA polymerase inhibitors such as rifamycin SV and rifampin (80-fold and 20-fold, respectively). In pilot screening experiments, we found actinomycete isolates successfully at an incidence of 1.9% (18/945) that produced antibacterials that were detectable only with RIK543 as the test organism. Strain RIK543 may be a feasible test organism for the discovery of novel RNA polymerase inhibitors. PMID:23335737

Tanaka, Yukinori; Nanamiya, Hideaki; Yano, Koichi; Kakugawa, Koji; Kawamura, Fujio

2013-01-01

54

Engineering feasibility analysis for in-situ stabilization of Canonsburg residues. [UMTRA project  

SciTech Connect

The US Department of Energy is considering several methods for carrying out remedial actions in Canonsburg, Pennsylvania, at the site of an inactive uranium-processing mill. The main objective of this study is to determine the feasibility of in-situ stabilization as the remedial action. In-situ stabilization is an alternative to site decontamination and offsite disposal. The problems associated with offsite hauling of large quantities of contaminated material and with the location and development of a new disposal site could be avoided by the implementation of an in-situ stabilization concept. In addition, the in-situ approach would be more cost-effective than offsite disposal. This study will establish that a technically feasible and implementable in-situ stabilization concept can be developed that meets regulatory requirements and is cost effective. This study in no way commits the DOE to implement any specific actions described herein. 11 refs., 30 figs., 24 tabs.

Not Available

1982-01-01

55

Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME  

SciTech Connect

The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen’s significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an analysis of test results indicates that hydrogen enhanced natural gas HCCI (versus neat natural gas HCCI at comparable stoichiometry) had the following characteristics: • Substantially lower intake temperature needed for stable HCCI combustion • Inconclusive impact on engine BMEP and power produced, • Small reduction in the thermal efficiency of the engine, • Moderate reduction in the unburned hydrocarbons in the exhaust, • Slight increase in NOx emissions in the exhaust, • Slight reduction in CO2 in the exhaust. • Increased knocking at rich stoichiometry The major accomplishments and findings from the project can be summarized as follows: 1. A model was calibrated for accurately predicting heat release rate and peak pressures for HCCI combustion when operating on hydrogen and natural gas blends. 2. A single cylinder research engine was thoroughly mapped to compare performance and emissions for micro-pilot natural gas compression ignition, and HCCI combustion for neat natural gas versus blends of natural gas and hydrogen.

Pratapas, John; Mather, Daniel; Kozlovsky, Anton

2013-03-31

56

Experimental research made during a city cycle on the feasibility of electrically charged SI engines  

NASA Astrophysics Data System (ADS)

The paper presents experimental research on performance improvements in a city cycle (operating mostly transient) of a compact class vehicle equipped with a turbocharged SI engine which had attached an electric charger, to improve engine response at low operational speeds. During tests, functional parameters, energy consumption of the electric charger and vehicle performances were measured while driving in two operating conditions: with active and inactive electric charger. The tests were carried out on a well-defined path, in the same driving style, by the same driver.

Kocsis, Levente B.; Burnete, Nicolae

2014-06-01

57

75 FR 64216 - Interpretation of OSHA's Provisions for Feasible Administrative or Engineering Controls of...  

Federal Register 2010, 2011, 2012, 2013

...1910.95(b)(1) in light of ATMI. Sun Ship, Inc., 11 BNA OSHC 1028 (No. 16118...engineering controls against their costs. Sun Ship, 11 BNA OSHC at 1031-32. Administrative...1037-43. In 1984, the Commission overruled Sun Ship in a split decision in which the...

2010-10-19

58

Regional Differences Among Estuaries  

NSDL National Science Digital Library

This text discusses differences in estuaries in different regions of the United States. It contrasts the fjord-like estuaries of the rocky Maine coast with the sandy barrier beaches, islands, and enclosed bays and sounds further south. The site also calls attention to the difference between the East Coast and the Northwest coast of emergence. The point is made that although they differ, all estuaries have great value and many are in danger.

Oberrecht, Kenn

2007-01-20

59

Regional Differences Among Estuaries  

NSDL National Science Digital Library

This text discusses differences in estuaries in different regions of the United States. It contrasts the fjord-like estuaries of the rocky Maine coast with the sandy barrier beaches, islands, and enclosed bays and sounds further south. The site also calls attention to the difference between the East Coast and the Northwest coast of emergence. The point is made that although they differ, all estuaries have great value and many are in danger.

60

Learning Lessons from Estuaries  

ERIC Educational Resources Information Center

There is something that draws all people to the sea and especially to the fertile estuaries that nuzzle up to its shores. An estuary serves as both a nursery and a grave for sea creatures. If life evolved from some primordial sea, it may well have been an estuary--a place where ocean and rivers meet and fresh and salty waters mingle in the…

Schnittka, Christine

2006-01-01

61

Nutrients in an Estuary  

NSDL National Science Digital Library

In this activity, learners model estuaries, artificially enriching both fresh and salt water samples with different amounts of nutrients and observing the growth of algae over several weeks. Learners relate their results to the phenomenon of algae blooms in estuaries. Learners then analyze data for different sites at the Guana Tolomato Matanzas National Estuarine Research Reserve (GTMNERR) in Florida to discover the relationships between nitrogen, chlorophyll, and dissolved oxygen. Finally, learners study how nutrients cycle through an estuary and suggest recommendations for reducing nutrient inputs to estuary waters.

Terc; National Oceanic and Atmospheric Administration (NOAA)

2012-06-26

62

Engineering geologic feasibility of lignite mining in alluvial valleys by hydraulic dredging methods  

E-print Network

Valleys Page 70 72 73 75 86 86 88 88 90 91 92 93 94 95 EVALUATION OF A POTENTIAL HYDRAULIC DREDGING TEST MINE SITE Location Haseline Information and Evaluations Regional Geology . Local Geology Stratigraphy . Topography Soil... 1 through 16, hypothetical dredge mine 4 Production data for pits 1 through 9, hypothetical surface mine Page 20 71 81 84 5 Engineering properties of Kaufman and Falba-Arol soils . 122 6 Description of overburden core 3332. SS 7...

Cason, Cynthia Lynn

2012-06-07

63

JT8D and JT9D jet engine performance improvement program. Task 1: Feasibility analysis  

NASA Technical Reports Server (NTRS)

JT8D and JT9D component performance improvement concepts which have a high probability of incorporation into production engines were identified and ranked. An evaluation method based on airline payback period was developed for the purpose of identifying the most promising concepts. The method used available test data and analytical models along with conceptual/preliminary designs to predict the performance improvements, weight, installation characteristics, cost for new production and retrofit, maintenance cost, and qualitative characteristics of candidate concepts. These results were used to arrive at the concept payback period, which is the time required for an airline to recover the investment cost of concept implementation.

Gaffin, W. O.; Webb, D. E.

1979-01-01

64

Georgia Estuaries Circulation Survey  

Microsoft Academic Search

The 1980 Circulation Survey, Southeast Atlantic Coast Estuaries, Sapelo Sound to St. Andrew Sound, Georgia, was conducted from March through June 1980 by the National Oceanic and Atmospheric Administration's Ship FERREL. Sapelo Sound, Doboy Sound, Altamaha Sound, St. Simons Sound, and their tributaries (collectively referred to as Georgia Estuaries) were studied. Current, tide, meteorological, and conductivity-temperature\\/depth data were collected. These

S. McCoy; W. Watson

1983-01-01

65

National Estuary Program  

NSDL National Science Digital Library

Estuaries are places where rivers meet the sea and are critical to the health of coastal environments and our enjoyment of them. Website features abundant information on the legal and scientific aspects of estuary preservation. Includes guidelines, program profiles, and a shorter version in Spanish. Resources for teachers and students include games and activities. External links to additional programs also provided.

66

Evaluating the feasibility of utilizing the small molecule phenamil as a novel biofactor for bone regenerative engineering.  

PubMed

Osteoblast cell adhesion and differentiation on biomaterials are important achievements necessary for implants to be useful in bone regenerative engineering. Recombinant bone morphogenetic proteins (BMPs) have been shown to be important for these processes; however, there are many challenges associated with the widespread use of these proteins. A recent report demonstrated that the small molecule phenamil, a diuretic derivative, was able to induce osteoblast differentiation and mineralization in vitro via the canonical BMP signalling cascade (Park et al., 2009). In this study, the feasibility of using phenamil as a novel biofactor in conjunction with a biodegradable poly(lactide-co-glycolide acid) (PLAGA) polymeric scaffold for engineering bone tissue was evaluated. The in vitro cellular behaviour of osteoblast-like MC3T3-E1 cells cultured on PLAGA scaffolds in the presence of phenamil at 10??M were characterized with regard to initial cell adhesion, proliferation, alkaline phosphatase (ALP) activity and matrix mineralization. The results demonstrate that phenamil supported cell proliferation, promoted ALP activity and facilitated matrix mineralization of osteoblast-like MC3T3-E1 cells. Moreover, in this study, we found that phenamil promoted integrin-mediated cell adhesion on PLAGA scaffolds. It was also shown that phenamil encapsulated within porous, microsphere PLAGA scaffolds retained its osteogenic activity upon release. Based on these findings, the small molecule phenamil has the potential to serve as a novel biofactor for the repair and regeneration of bone tissues. PMID:22815259

Lo, Kevin W-H; Ulery, Bret D; Kan, Ho Man; Ashe, Keshia M; Laurencin, Cato T

2014-09-01

67

Engineering practice variation through provider agreement: a cluster-randomized feasibility trial  

PubMed Central

Purpose Minimal-risk randomized trials that can be embedded in practice could facilitate learning health-care systems. A cluster-randomized design was proposed to compare treatment strategies by assigning clusters (eg, providers) to “favor” a particular drug, with providers retaining autonomy for specific patients. Patient informed consent might be waived, broadening inclusion. However, it is not known if providers will adhere to the assignment or whether institutional review boards will waive consent. We evaluated the feasibility of this trial design. Subjects and methods Agreeable providers were randomized to “favor” either hydrochlorothiazide or chlorthalidone when starting patients on thiazide-type therapy for hypertension. The assignment applied when the provider had already decided to start a thiazide, and providers could deviate from the strategy as needed. Prescriptions were aggregated to produce a provider strategy-adherence rate. Results All four institutional review boards waived documentation of patient consent. Providers (n=18) followed their assigned strategy for most of their new thiazide prescriptions (n=138 patients). In the “favor hydrochlorothiazide” group, there was 99% adherence to that strategy. In the “favor chlorthalidone” group, chlorthalidone comprised 77% of new thiazide starts, up from 1% in the pre-study period. When the assigned strategy was followed, dosing in the recommended range was 48% for hydrochlorothiazide (25–50 mg/day) and 100% for chlorthalidone (12.5–25.0 mg/day). Providers were motivated to participate by a desire to contribute to a comparative effectiveness study. A study promotional mug, provider information letter, and interactions with the site investigator were identified as most helpful in reminding providers of their study drug strategy. Conclusion Providers prescribed according to an assigned drug-choice strategy most of the time for the purpose of a comparative effectiveness study. This simple design could facilitate research participation and behavior change in non-research clinicians. Waiver of patient consent can broaden the representation of patients, providers, and settings.

McCarren, Madeline; Twedt, Elaine L; Mansuri, Faizmohamed M; Nelson, Philip R; Peek, Brian T

2014-01-01

68

Feasibility of using a high-level waste canister as an engineered barrier in disposal  

SciTech Connect

The objective of this report is to evaluate the feasibility of designing a process canister that could also serve as a barrier canister. To do this a general set of performance criteria is assumed and several metal alloys having a high probability of demonstrating high corrosion resistance under repository conditions are evaluated in a qualitative design assessment. This assessment encompasses canister manufacture, the glass-filling process, interim storage, transportation, and to a limited extent, disposal in a repository. A series of scoping tests were carried out on two titanium alloys and Inconel 625 to determine if the high temperature inherent in the glass-fill processing would seriously affect either the strength or corrosion resistance of these metals. This is a process-related concern unique to the barrier canister concept. The material properties were affected by the heat treatments which simulated both the joule-heated glass melter process (titanium alloys and Inconel 625) and the in-can melter (ICM) process (Inconel 625). However, changes in the material properties were generally within 20% of the original specimens. Accelerated corrosion testing of the heat treated coupons in a highly oxygenated brine showed basic corrosion resistance of titanium grade 12 and Inconel 625 to compare favorably with that of the untreated coupons. The titanium grade 2 coupons experienced severe corrosion pitting. These corrosion tests were of a scoping nature and suitable primarily for the detection of gross sensitivity to the heat treatment inherent in the glass-fill process. They are only suggstive of repository performance since the tests do not adequately model the wide range of repository conditions that could conceivably occur.

Slate, S.C.; Pitman, S.G.; Nesbitt, J.F.; Partain, W.L.

1982-08-01

69

Boron neutron capture therapy applied to advanced breast cancers: Engineering simulation and feasibility study of the radiation treatment protocol  

NASA Astrophysics Data System (ADS)

This dissertation describes a novel Boron Neutron Capture Therapy (BNCT) application for the treatment of human epidermal growth factor receptor type 2 positive (HER2+) breast cancers. The original contribution of the dissertation is the development of the engineering simulation and the feasibility study of the radiation treatment protocol for this novel combination of BNCT and HER2+ breast cancer treatment. This new concept of BNCT, representing a radiation binary targeted treatment, consists of the combination of two approaches never used in a synergism before. This combination may offer realistic hope for relapsed and/or metastasized breast cancers. This treatment assumes that the boronated anti-HER2 monoclonal antibodies (MABs) are administrated to the patient and accumulate preferentially in the tumor. Then the tumor is destroyed when is exposed to neutron irradiation. Since the use of anti-HER2 MABs yields good and promising results, the proposed concept is expected to amplify the known effect and be considered as a possible additional treatment approach to the most severe breast cancers for patients with metastasized cancer for which the current protocol is not successful and for patients refusing to have the standard treatment protocol. This dissertation makes an original contribution with an integral numerical approach and proves feasible the combination of the aforementioned therapy and disease. With these goals, the dissertation describes the theoretical analysis of the proposed concept providing an integral engineering simulation study of the treatment protocol. An extensive analysis of the potential limitations, capabilities and optimization factors are well studied using simplified models, models based on real CT patients' images, cellular models, and Monte Carlo (MCNP5/X) transport codes. One of the outcomes of the integral dosimetry assessment originally developed for the proposed treatment of advanced breast cancers is the implementation of BNCT for HER2+ breast cancers for deep seated tumors using MITRII-FCB facility with an 8 cm diameter beam (port closest-to-tumor position), with boron concentrations in the tumor higher than 32 mug/g, and for a tumor-to-healthy tissue boron concentration ratio of 8:1. The therapeutic ratios for the proposed treatment would be higher than five for skin and adipose tissue and higher than three for tumor surrounding fibroglandular tissue. The microdosimetry study shows potential improvements in the therapeutic ratios based on the expected sub-cellular boron biodistributions. The engineering simulation study of clinical cases shows the advantages of using BNCT for HER+ breast cancers. Assuming an assured high efficiency of the boron agent delivery, the proposed concept can be considered for stage IV HER2+ breast cancers in treating the metastasized tumors in brain, head and neck, and lungs.

Sztejnberg Goncalves-Carralves, Manuel Leonardo

70

Feasibility of Conducting J-2X Engine Testing at the Glenn Research Center Plum Brook Station B-2 Facility  

NASA Technical Reports Server (NTRS)

A trade study of the feasibility of conducting J-2X testing in the Glenn Research Center (GRC) Plum Brook Station (PBS) B-2 facility was initiated in May 2006 with results available in October 2006. The Propulsion Test Integration Group (PTIG) led the study with support from Marshall Space Flight Center (MSFC) and Jacobs Sverdrup Engineering. The primary focus of the trade study was on facility design concepts and their capability to satisfy the J-2X altitude simulation test requirements. The propulsion systems tested in the B-2 facility were in the 30,000-pound (30K) thrust class. The J-2X thrust is approximately 10 times larger. Therefore, concepts significantly different from the current configuration are necessary for the diffuser, spray chamber subsystems, and cooling water. Steam exhaust condensation in the spray chamber is judged to be the key risk consideration relative to acceptable spray chamber pressure. Further assessment via computational fluid dynamics (CFD) and other simulation capabilities (e.g. methodology for anchoring predictions with actual test data and subscale testing to support investigation.

Schafer, Charles F.; Cheston, Derrick J.; Worlund, Armis L.; Brown, James R.; Hooper, William G.; Monk, Jan C.; Winstead, Thomas W.

2008-01-01

71

A simulation of estuary response to training wall construction using a regime approach  

Microsoft Academic Search

A method, based on regime theory, for the long-term prediction of the effects of civil engineering works on estuaries with muddy sediment conditions is described. The method involves the use of a hybrid model consisting of a 1D flow model, to describe the estuary geometry, coupled with a discharge\\/area algorithm to simulate the changes in estuary morphology. The flow model

J. R. Spearman; M. P. Dearnaley; J. M. Dennis

1998-01-01

72

Estuarine Science: All About Estuaries  

NSDL National Science Digital Library

Estuaries are partially enclosed bodies of water along coastlines where fresh water and salt water meet and mix. They act as a transition zone between oceans and continents. This site examines various aspects of estuaries, focusing on the geological features that make an estuary, as well as the water circulation patterns by which they are classified. It also has a section that allows the user to access additional text and graphics on many of the estuaries of the world.

73

JT9D engine diagnostics. Task 2: Feasibility study of measuring in-service flight loads. [747 aircraft performance  

NASA Technical Reports Server (NTRS)

The feasibility of measuring JT9D propulsion system flight inertia loads on a 747 airplane is studied. Flight loads background is discussed including the current status of 747/JT9D loads knowledge. An instrumentation and test plan is formulated for an airline-owned in-service airplane and the Boeing-owned RA001 test airplane. Technical and cost comparisons are made between these two options. An overall technical feasibility evaluation is made and a cost summary presented. Conclusions and recommendations are presented in regard to using existing inertia loads data versus conducting a flight test to measure inertia loads.

Kafka, P. G.; Skibo, M. A.; White, J. L.

1977-01-01

74

Feasibility study of the utilization of residual engine heat for the operation of an automotive, absorption-type, air conditioner  

Microsoft Academic Search

The problem of this study was to build and test an absorption-type air-conditioning system for automotive use that would utilize residual engine heat. The engine was used as the system's generator and the radiator was used as the system's absorber. The intent of the testing was to determine harmful affects the system may produce and how effective the system was

1987-01-01

75

Distribution and Invasion Potential of Limonium ramosissimum subsp. provinciale in San Francisco Estuary Salt Marshes  

E-print Network

Survey Pacific Science Center. Jepson Flora Project: JepsonScience and Engineering, the ARCS Foundation, the South Bay Salt Ponds Restoration Project,Project. Malta: Council of Europe. SAN FRANCISCO ESTUARY & WATERSHED SCIENCE

Archbald, Gavin; Boyer, Katharyn E.

2014-01-01

76

IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 15, NO. 2, JUNE 2007 295 Feasibility of Prosthetic Posture Sensing  

E-print Network

torques required for limb movement. Mi- croimplants called BIONs (BIOnic neurons) [1] have been de Feasibility of Prosthetic Posture Sensing Via Injectable Electronic Modules Wei Tan, Member, IEEE, and Gerald caused by the shapes of the internal and external coils, ferrite material, and electronic connections

Loeb, Gerald E.

77

Ecology of estuaries  

SciTech Connect

This book is a summary of information available on estuarine ecology, that reviews concepts and problems of estuaries and assesses the value of these coastal systems. It investigates such topics as water circulation and mixing, trace elements, nutrients, organic matter, and sedimentary processes, with reviews on more than two decades of intense study. Chapters reflect contributions from a variety of interdisciplinary sciences including botany, chemistry, ecology, geology, physics, and zoology.

Kennish, M.J.

1986-01-01

78

A two-phase numerical model for suspended-sediment transport in estuaries  

Microsoft Academic Search

This paper presents a full 2-D X\\/Z numerical model for sediment transport in open channels and estuaries using a two-phase (fluid–solid particle) approach. The physical concept and the mathematical background of the model are given and test-cases have been carried out to validate the proposed model. In order to illustrate its feasibility for a real estuary, the model has been

Kim Dan Nguyen; Sylvain Guillou; Julien Chauchat; Nathaly Barbry

2009-01-01

79

Estuaries are not so unique  

Microsoft Academic Search

The applicability of recent theories relating tides and river flow to estuarine bathymetry has been assessed against observations from UK estuaries. These theories, combined with observations, show that variations between estuaries are limited by how tides and river flow control sediments and bathymetry. Typical ages were determined from differences between theoretical and observed depths for Rias (11000 years), Coastal Plain

David Prandle; Andrew J. Manning

2005-01-01

80

Monitoring and Managing Water Quality in the San Francisco Estuary San Francisco Estuary Institute and the  

E-print Network

Monitoring and Managing Water Quality in the San Francisco Estuary San Francisco Estuary Institute and the Regional Monitoring Program for Water Quality in the San Francisco Estuary #12;www.sfei.org #12;Contribution 517 Monitoring and Managing Water Quality in the San Francisco Estuary San Francisco Estuary

81

DC-9/JT8D refan, Phase 1. [technical and economic feasibility of retrofitting DC-9 aircraft with refan engine to achieve desired acoustic levels  

NASA Technical Reports Server (NTRS)

Analyses and design studies were conducted on the technical and economic feasibility of installing the JT8D-109 refan engine on the DC-9 aircraft. Design criteria included minimum change to the airframe to achieve desired acoustic levels. Several acoustic configurations were studied with two selected for detailed investigations. The minimum selected acoustic treatment configuration results in an estimated aircraft weight increase of 608 kg (1,342 lb) and the maximum selected acoustic treatment configuration results in an estimated aircraft weight increase of 809 kg (1,784 lb). The range loss for the minimum and maximum selected acoustic treatment configurations based on long range cruise at 10 668 m (35,000 ft) altitude with a typical payload of 6 804 kg (15,000 lb) amounts to 54 km (86 n. mi.) respectively. Estimated reduction in EPNL's for minimum selected treatment show 8 EPNdB at approach, 12 EPNdB for takeoff with power cutback, 15 EPNdB for takeoff without power cutback and 12 EPNdB for sideline using FAR Part 36. Little difference was estimated in EPNL between minimum and maximum treatments due to reduced performance of maximum treatment. No major technical problems were encountered in the study. The refan concept for the DC-9 appears technically feasible and economically viable at approximately $1,000,000 per airplane. An additional study of the installation of JT3D-9 refan engine on the DC-8-50/61 and DC-8-62/63 aircraft is included. Three levels of acoustic treatment were suggested for DC-8-50/61 and two levels for DC-8-62/63. Results indicate the DC-8 technically can be retrofitted with refan engines for approximately $2,500,000 per airplane.

1973-01-01

82

Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary, Annual Report of Research  

Microsoft Academic Search

In 2002 with support from the U.S. Army Corps of Engineers (USACE), an interagency research team began investigating salmon life histories and habitat use in the lower Columbia River estuary to fill significant data gaps about the estuary's potential role in salmon decline and recovery . The Bonneville Power Administration (BPA) provided additional funding in 2004 to reconstruct historical changes

Daniel L. Bottom; Charles A. Simenstad; Lance Campbell

2009-01-01

83

Evaluation of feasibility of measuring EHD film thickness associated with cryogenic fluids. [for space shuttle main engine bearings  

NASA Technical Reports Server (NTRS)

The feasibility of measuring elastohydrodynamic (EHD) films as formed with a cryogenic (LN2) fluid is evaluated. Modifications were made to an existing twin disk EHD apparatus to allow for disk lubrication with liquid nitrogen. This disk apparatus is equipped with an X-ray system for measuring the thickness of any lubricant film that is formed between the disks. Several film thickness experiments were conducted with the apparatus which indicate that good lubrication films are filmed with LN2. In addition to the film thickness studies, failure analyses of three bearings were conducted. The HPOTP turbine end bearings had experienced axial loads of 36,000 to 44,000 N (8,000 to 10,000 lb). High continuous radial loads were also experienced, which were most likely caused by thermal growth of the inner race. The resulting high internal loads caused race spalling and ball wear to occur.

Kannel, J. W.; Merriman, T. L.; Stockwell, R. D.; Dufrane, K. F.

1983-01-01

84

Session III: Estuary Columbia River Estuary overview of physical features and habitats  

E-print Network

and river flow. About 71% of the lower estuary is deep. Temperatures in the estuary vary with depth the wetland plants is the basis for the food web in the estuary, supplemented by algal production from

85

Stream, lake, estuary, and ocean pollution, 2nd edition  

SciTech Connect

This book, an updated version of the 1985 edition, contains thirteen chapters, beginning with a preface which provides the objective of the book. The primary objective is to offer a comprehensive survey of the biological, hydrological, mathematical, and biochemical aspects of stream, lake, estuary, and ocean pollution analysis. The book also contains ten appendices of useful tables and nomographs of pertinent data. This book provides a very good summary and review of stream, lake, estuary, and ocean pollution. This book is recommended for environmental engineering students, environmental consulting engineers, and regulatory personnel. It provides an excellent summary of the field of stream and lake analysis and modeling. Every chapter includes a significant number of questions and pertinent references.

Nemerow, N.L. (ed.)

1991-01-01

86

PECONIC ESTUARY EELGRASS HABITAT CRITERIA STUDY  

EPA Science Inventory

PECONIC ESTUARY EELGRASS HABITAT CRITERIA STUDY The main objective of this study is to develop criteria for eelgrass habitat establishment and persistence within the Peconic Estuary utilizing various environmental analyses. The Program evaluated water and sediment quality data to...

87

Estuaries and Clean Water Act of 2000  

NSDL National Science Digital Library

The Office of Water at the Environmental Protection Agency has posted online this document on the new Estuaries and Clean Water Act of 2000. Available in .pdf format, the document summarizes the Act, which emphasizes restoration of estuary habitat.

88

Estuaries: Where Rivers Meet the Sea  

NSDL National Science Digital Library

Take your students on an EstuaryLive telecast! EstuaryLive brings free, live internet field trips in four different estuaries around the country, right to your classroom. These online field trips are the next best thing to an actual trip to an estuary, providing students with an exciting and new way to learn about unique estuarine ecosystems. The site also includes archived webcasts and teacher resources including classroom activities and a glossary.

2011-05-16

89

Estuaries: Where Rivers Meet the Sea  

NSDL National Science Digital Library

Take your students on an EstuaryLive telecast! EstuaryLive brings free, live internet field trips in four different estuaries around the country, right to your classroom. These online field trips are the next best thing to an actual trip to an estuary, providing students with an exciting and new way to learn about unique estuarine ecosystems. The site also includes archived webcasts and teacher resources including classroom activities and a glossary.

90

Feasibility and limitations of the round robin test for assessment of in vitro chondrogenesis evaluation protocol in a tissue-engineered medical product.  

PubMed

Tissue-engineered medical products (TEMPs) should be evaluated before implantation. Therefore, it is indispensable to establish evaluation protocols in regenerative medicine. Whether or not such evaluation protocols are reasonable is generally verified through a 'round robin' test. However, the round robin test for TEMPs intrinsically includes a deficiency, because 'identical' specimens can not be prepared for TEMPs. The aim of the study was to assess the feasibility and limitations of the round robin test for TEMPs by using a prepared evaluation protocol. We adopted tissue-engineered cartilage constructs as delivered specimens and a protocol of measuring sGAG content as an evaluation protocol proposed to ISO TC150/SC7, which is an invasive, but usually applied, method, although non-invasive methods are keenly required in evaluating TEMPs. The results showed that: (a) the coefficient of variation (CV) of the measured sGAG contents in intralaboratory tests was ~5% at most; (b) the CV of sGAG content in the scheme where each participating laboratory measured different constructs was comparable with that in the scheme where each participating laboratory measured one half of a construct along with the organizing laboratory; (c) the CV caused by factors other than the specimen was ~15%, comparable to that in reproducible experiments in biomedical fields. Based on these results, the study concludes that a round robin test for a TEMP could be valuable, under the condition that the delivered TEMPs are sufficiently reproducible so that the CV of the measured values is?

Yokoi, Masako; Hattori, Koji; Narikawa, Koichi; Ohgushi, Hajime; Tadokoro, Mika; Hoshi, Kazuto; Takato, Tsuyoshi; Myoui, Akira; Nanno, Katsuhiko; Kato, Yukio; Kanawa, Masami; Sugawara, Katsura; Kobo, Tomoko; Ushida, Takashi

2012-07-01

91

PECONIC ESTUARY STORMWATER ASSESSMENT AND PLANNING TOOL  

EPA Science Inventory

PECONIC ESTUARY STORMWATER ASSESSMENT AND PLANNING TOOL Horsley & Witten, Inc. was contracted by the Peconic Estuary Program to create a Regional Stormwater Runoff Management Plan designed to mitigate loadings of fecal coliform bacteria and nitrogen to the Peconic Estuary. The pu...

92

Ecology of estuaries: Anthropogenic effects  

SciTech Connect

Estuaries and near-shore oceanic water are subjected to a multitude of human wastes. The principal objective of this book is to examine anthropogenic effects on estuaries, and it focuses primarily on contaminants in coastal systems. Covered within various chapters are the following topics: waste disposal strategies; definition and classification of pollutants (including organic loading, oil pollution, polynuclear aromatic hydrocarbons; chlorinated hydrocarbons; heavy metals; radionuclides) biological impacts; waste management; impacts of power plants; dredging and spoil disposal; case studies, primarily Chesapeake Bay. The book serves as a text and as a reference.

Kennish, M.J.

1992-01-01

93

Valuing environmental water pulses into the Incomati estuary: Key to achieving equitable and sustainable utilisation of transboundary waters  

NASA Astrophysics Data System (ADS)

Upstream developments in the Incomati river basin, shared by South Africa, Swaziland and Mozambique, have altered downstream flows significantly. The frequency of small floods into the estuary has been reduced dramatically. This change in the flow regime has impacted on the state of the environment downstream, and the Incomati estuary in particular. The estuary requires fresh water pulses that naturally occur, and the resulting seasonal flooding of the plains. Resource-poor rural households depend on the goods and services that the estuary and flood plains provide such as wood, charcoal, building materials, fish and shrimp, wetland farming, and tourism. Alteration of the flow regime into the estuary has a negative impact on the state of the environment and hence on the goods and services the estuary yields; a phenomenon the people living near the estuary are keenly aware of. The article estimates the value of the goods and services that the estuary currently provides, that is under the conditions of a changed flow regime. A linear relationship is then assumed between fresh water pulses into the estuary and the goods and services it provides, so that the order of magnitude of the economic value of fresh water pulses into the estuary may be approximated. Various development scenarios in the Incomati basin are then considered, that have different upstream and downstream impacts on water availability, and the basin-wide benefits and costs are compared. The paper concludes that the principle of sharing the benefits derived from the water resources, rather than the water itself, as proposed by authors such as [Sadoff, C.W., Grey, D., 2002. Beyond the river: the benefits of cooperation on international rivers. Water Policy 4, 389-403], may be a feasible approach only if the less tangible benefits and functions, especially those of the environment, are assigned an appropriate value and corresponding priority.

Sengo, D. José; Kachapila, Albert; Zaag, Pieter van der; Mul, Marloes; Nkomo, Sakhiwe

94

The Value of Healthy Estuaries  

NSDL National Science Digital Library

The article explores why healthy estuaries are critical to humans and wildlife: supporting both commercial and recreational fisheries, treating waste and runoff, protecting coastal areas from natural hazards, connect bodies of water for transportation, and nurturing a balance of the food web

Robert Christian (East Carolina University;)

2009-03-15

95

The Value of Healthy Estuaries  

NSDL National Science Digital Library

Healthy estuaries are critical to humans and wildlife. They provide food, supporting both commercial and recreational fisheries, treat waste and runoff to maintain water quality, protect coastal areas from natural hazards, connect bodies of water for transportation and marine operations, and nurture a balance of the food web upon which all life depends.

Robert Christian (Thomas Harriot College of Arts and Sciences;)

2009-03-22

96

Simulated Sampling of Estuary Plankton  

ERIC Educational Resources Information Center

To find out about the microscopic life in the valuable estuary environment, it is usually necessary to be near the water. This dry lab offers an alternative, using authentic data and a simulation of plankton sampling. From the types of organisms found in the sample, middle school students can infer relationships in the biological and physical…

Fortner, Rosanne W.; Jenkins, Deborah Bainer

2009-01-01

97

Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary, Annual Report of Research.  

SciTech Connect

In 2002 with support from the U.S. Army Corps of Engineers (USACE), an interagency research team began investigating salmon life histories and habitat use in the lower Columbia River estuary to fill significant data gaps about the estuary's potential role in salmon decline and recovery . The Bonneville Power Administration (BPA) provided additional funding in 2004 to reconstruct historical changes in estuarine habitat opportunities and food web linkages of Columbia River salmon (Onchorhynchus spp.). Together these studies constitute the estuary's first comprehensive investigation of shallow-water habitats, including selected emergent, forested, and scrub-shrub wetlands. Among other findings, this research documented the importance of wetlands as nursery areas for juvenile salmon; quantified historical changes in the amounts and distributions of diverse habitat types in the lower estuary; documented estuarine residence times, ranging from weeks to months for many juvenile Chinook salmon (O. tshawytscha); and provided new evidence that contemporary salmonid food webs are supported disproportionately by wetland-derived prey resources. The results of these lower-estuary investigations also raised many new questions about habitat functions, historical habitat distributions, and salmon life histories in other areas of the Columbia River estuary that have not been adequately investigated. For example, quantitative estimates of historical habitat changes are available only for the lower 75 km of the estuary, although tidal influence extends 217 km upriver to Bonneville Dam. Because the otolith techniques used to reconstruct salmon life histories rely on detection of a chemical signature (strontium) for salt water, the estuarine residency information we have collected to date applies only to the lower 30 or 35 km of the estuary, where fish first encounter ocean water. We lack information about salmon habitat use, life histories, and growth within the long tidal-fresh reaches of the main-stem river and many tidally-influenced estuary tributaries. Finally, our surveys to date characterize wetland habitats within island complexes distributed in the main channel of the lower estuary. Yet some of the most significant wetland losses have occurred along the estuary's periphery, including shoreline areas and tributary junctions. These habitats may or may not function similarly as the island complexes that we have surveyed to date. In 2007 we initiated a second phase of the BPA estuary study (Phase II) to address specific uncertainties about salmon in tidal-fresh and tributary habitats of the Columbia River estuary. This report summarizes 2007 and 2008 Phase II results and addresses three principal research questions: (1) What was the historic distribution of estuarine and floodplain habitats from Astoria to Bonneville Dam? (2) Do individual patterns of estuarine residency and growth of juvenile Chinook salmon vary among wetland habitat types along the estuarine tidal gradient? (3) Are salmon rearing opportunities and life histories in the restoring wetland landscape of lower Grays River similar to those documented for island complexes of the main-stem estuary? Phase II extended our analysis of historical habitat distribution in the estuary above Rkm 75 to near Bonneville Dam. For this analysis we digitized the original nineteenth-century topographic (T-sheets) and hydrographic (H-sheets) survey maps for the entire estuary. Although all T-sheets (Rkm 0 to Rkm 206) were converted to GIS in 2005 with support for the USACE estuary project, final reconstruction of historical habitats throughout the estuary requires completion of the remaining H-sheet GIS maps above Rkm 75 and their integration with the T-sheets. This report summarizes progress to date on compiling the upper estuary H-sheets above Rkm 75. For the USACE estuary project, we analyzed otoliths from Chinook salmon collected near the estuary mouth in 2003-05 to estimate variability in estuary residence times among juvenile out migrants. In Phase II we expanded these analyses to comp

Bottom, Daniel L.; Simenstad, Charles A.; Campbell, Lance [Northwest Fisheries Science Center

2009-05-15

98

75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...  

Federal Register 2010, 2011, 2012, 2013

...Policy task force goals and in identifying focus areas for the estuary habitat restoration strategy, such as: climate adaptation restoration, socio-economic benefits of estuary habitat restoration, and geographic restoration...

2010-06-21

99

MAPPING BATHYMETRY AND BOTTOM TYPE IN A SHALLOW ESTUARY  

EPA Science Inventory

Bathymetry and bottom type are important in characterizing estuaries and their ecology but hard to map, especially in shallow estuaries. Acoustic backscattering was used to remotely sense these properties in the shallow Slocums River Estuary of Massachusetts. Acoustic pulses were...

100

Comparison of Nutrient Drivers and Response Metrics in Oregon Estuaries  

EPA Science Inventory

With the goal of assessing sensitivity to nutrient enrichment, we present a cross-estuary comparison of nutrient sources, levels, and biological responses (phytoplankton and macroalgae) for thirteen Oregon estuaries. Nitrogen levels in the upstream portions of the estuaries are ...

101

DENSITY-DEPENDENT IMPACTS OF BIOIRRIGATION BY THE BURROWING SHRIMP UPOGEBIA PUGETTENSIS ON BENTHIC FLUXES AND POREWATER SOLUTE DISTRIBUTIONS IN PACIFIC NORTHWEST ESTUARIES  

EPA Science Inventory

Burrowing thalassinid shrimp are major ecosystem engineering species of Pacific estuaries and can structure the physical, chemical, and biotic properties of sediments. Feeding and burrow irrigation by benthic organisms can increase the remineralization rates of organic material (...

102

Morphology, hydrography and sediment dynamics in a mangrove estuary: The Konkoure Estuary, Guinea  

Microsoft Academic Search

The Konkouré Estuary in the Republic of Guinea is a poorly understood atypical mangrove system. Sediment dynamics in tropical estuaries are controlled by a combination of processes including river discharge, morphology, salinity, erosion and deposition processes, the settling of mud, physico-chemical processes and mangrove swamps. Here we present a consistent set of data aimed at characterising the estuary and thus,

S. Capo; A. Sottolichio; I. Brenon; P. Castaing; L. Ferry

2006-01-01

103

Nutrient cycling and foodwebs in Dutch estuaries  

Microsoft Academic Search

In this review several aspects of the functioning of the Dutch estuaries (Ems-Dollard, Wadden Sea, Oosterschelde, Westerschelde,\\u000a Grevelingen and Veerse Meer) have been compared. A number of large European rivers (especially Rhine) have a prevailing influence\\u000a on the nutrient cycling of most Dutch estuaries. Owing to the increased loading of the estuaries with nitrogen and phosphorus\\u000a compounds, effects of eutrophication

P. H. Nienhuis

1993-01-01

104

Morphodynamic equilibrium of alluvial estuaries  

NASA Astrophysics Data System (ADS)

The evolution of the longitudinal bed profile of an estuary, with given plan-form configuration, subject to given tidal forcing at the mouth and prescribed values of water and sediment supply from the river is investigated numerically. Our main goal is to ascertain whether, starting from some initial condition, the bed evolution tends to reach a unique equilibrium configuration asymptotically in time. Also, we investigate the morphological response of an alluvial estuary to changes in the tidal range and hydrologic forcing (flow and sediment supply). Finally, the solution helps characterizing the transition between the fluvially dominated region and the tidally dominated region of the estuary. All these issues play an important role also in interpreting how the facies changes along the estuary, thus helping to make correct paleo-environmental and sequence-stratigraphic interpretations of sedimentary successions (Dalrymple and Choi, 2007). Results show that the model is able to describe a wide class of settings ranging from tidally dominated estuaries to fluvially dominated estuaries. In the latter case, the solution is found to compare satisfactory with the analytical asymptotic solution recently derived by Seminara et al. (2012), under the hypothesis of fairly 'small' tidal oscillations. Simulations indicate that the system always moves toward an equilibrium configuration in which the net sediment flux in a tidal cycle is constant throughout the estuary and equal to the constant sediment flux discharged from the river. For constant width, the bed equilibrium profile of the estuarine channel is characterized by two distinct regions: a steeper reach seaward, dominated by the tide, and a less steep upstream reach, dominated by the river and characterized by the undisturbed bed slope. Although the latter reach, at equilibrium, is not directly affected by the tidal wave, however starting from an initial uniform stream with the constant 'fluvial' slope, the final equilibrium state is reached through an erosional wave, which leads to bed degradation of the upstream 'fluvial reach'. For a given river discharge, the length of the tidal reach increases quite rapidly with tidal amplitude, up to some threshold value of the tidal amplitude above which the length of the estuary becomes comparable with the length of the tidal wave. When the channel plan-form is convergent, deposition of sediments of fluvial origin in the funnel-shaped region drastically changes the equilibrium configuration. The effect of an increasing channel convergence is thus to induce bed aggradation close to the inlet. Nevertheless, tidal forcing only slightly changes the non-tidal profile. The effect of increasing tidal oscillations again leads to an increase of the bed slope at the inlet and to a general bed degradation upstream. The effects of varying sediment supply, flow discharge and river width in the upstream reach have also been investigated and play an important role. Further geomorphological implications of these results will be discussed at the meeting. References Dalrymple, R. W., and K. Choi (2007), Morphologic and facies trends through the fluvialmarine transition in tide-dominated depositional systems: A schematic framework for environmental and sequence-stratigraphic interpretation, Earth-Science Reviews, 81(3-4), 135-174, doi:10.1016/j.earscirev.2006.10.002. Seminara, G., M. Bolla Pittaluga, and N. Tambroni (2012), Morphodynamic equilibrium of tidal channels, Environmental Fluid Mechanics: Memorial Volume in Honour of Prof. Gerhard H. Jirka, 153-174

Tambroni, Nicoletta; Bolla Pittaluga, Michele; Canestrelli, Alberto; Lanzoni, Stefano; Seminara, Giovanni

2014-05-01

105

New Bedford Harbor Superfund Project, Acushnet River estuary engineering feasibility study of dredging and dredged material disposal alternatives. Report 4. Surface runoff quality evaluation for confined disposal. Technical report, June-February 1987  

SciTech Connect

The thickness of capping material needed to chemically sequests the polychlorinated biphenyl (PCB)-contaminated New Bedford Harbor sediment from the overlying water column and aquatic biota was assessed in a small-scale predictive test. Changes in the overlying water concentrations of dissolved oxygen, ammonium-nitrogen, and orthophosphate-phosphorus were monitored following isolation of the water column from the atmosphere by placing a 4-cm layer of mineral oil on the water surface. The chemical tracers (ammonium-nitrogen and orthophosphate-phosphorus) were selected for their mobility under anaerobic conditions, ease of measurement, and generally high concentrations in contaminated dredged material compared with clean sediments. The chemical tracers were used to evaluate the efficiency of the capping material in preventing transfer of contaminants from New Bedford Harbor sediment into the overlying water column.

Skogerboe, J.G.; Price, R.A.; Brandon, D.L.

1988-10-01

106

New Bedford Harbor Superfund project, Acushnet River estuary engineering-feasibility study of dredging and dredged-material disposal alternatives. Report 8. Compatibility of liner systems with New Bedford Harbor dredged-material contaminants. Technical report, January-June 1987  

SciTech Connect

New Bedford Harbor sediments contain substantial amounts of both organic and inorganic contaminants. Leaching studies with this sediment indicate that the leachate generated from the disposal of these sediments may contain significant amounts of the same contaminants. This investigation examined the available literature and data pertaining to the chemical compatibility of synthetic and natural liners with both organic and inorganic contaminants. Although compatibility testing with various liner materials and leachate with contaminant concentrations exactly like New Bedford Harbor sediment leachate is not available, testing with contaminant mixtures similar to and with higher concentrations has indicated no significant compatibility problems. Lining experience has shown that, with low contaminant-concentration mixtures such as the leachate generated from disposal of New Bedford Harbor sediments, problems with installation may be of more concern than liner compatibility.

Shafer, R.A.

1988-10-01

107

Protocols for Monitoring Habitat Restoration Projects in the Lower Columbia River and Estuary  

SciTech Connect

Protocols for monitoring salmon habitat restoration projects are essential for the U.S. Army Corps of Engineers' environmental efforts in the Columbia River estuary. This manual provides state-of-the science data collection and analysis methods for landscape features, water quality, and fish species composition, among others.

Roegner, G. Curtis; Diefenderfer, Heida L.; Borde, Amy B.; Thom, Ronald M.; Dawley, Earl M.; Whiting, Allan H.; Zimmerman, Shon A.; Johnson, Gary E.

2008-04-25

108

Migratory Behavior and Survival of Juvenile Salmonids in the Lower Columbia River and Estuary in 2009  

Microsoft Academic Search

The study reported herein was funded as part of the Anadromous Fish Evaluation Program, which is managed by the U.S. Army Corps of Engineers (USACE). The Anadromous Fish Evaluation Program study code is EST P 02 01: A Study of Salmonid Survival and Behavior through the Columbia River Estuary Using Acoustic Tags. The study was conducted by the Pacific Northwest

Geoffrey A. McMichael; Ryan A. Harnish; Brian J. Bellgraph; Jessica A. Carter; Kenneth D. Ham; P. Scott Titzler; Michael S. Hughes

2010-01-01

109

Towards medium-term (order of months) morphodynamic modelling of the Teign estuary, UK  

NASA Astrophysics Data System (ADS)

The main objective of this paper is to address the principal mechanisms involved in the medium-term (order of months to years) morphodynamic evolution of estuaries through the application of a process-based numerical modelling. The Teign estuary (Teignmouth, UK) is the selected site. The system is forced by the macrotidal semi-diurnal tide in the English Channel and is perturbed to a minor extent by high river discharge events (freshets). Although waves have a definite influence on the adjacent coastal area, Wells (Teignmouth Quay Development Environmental Statement: Changes to Physical Processes. Report R.984c:140. ABP Marine Environmental Research Ltd., Southampton, 2002b) suggested that swell waves do not enter the estuary. Hence, wave effects are neglected in this study, as only tides and the river discharge are taken into account. The sediment grain size is highly variable, but mainly sandy. Within the frame of the COAST3D project ( http://www.hrwallingford.co.uk/projects/COAST3D ), four bathymetric surveys of the adjacent coastal area were carried out at a nearly weekly intervals. The outer estuary and the adjacent coastal area were also surveyed every 6 months as part of the COASTVIEW project ( http://thecoastviewproject.org ). Based on these data and on continuously measured parameters, such as water level, waves, wind and river discharge, numerical modelling of the morphodynamic processes can be tested. To replicate the morphological changes in the medium-term within a feasible simulation time, forcing conditions are reduced through the use of an input reduction method (called ensemble technique). In this study, simulations are based on the coupling between Telemac-2D and its non-cohesive sediment transport module, Sisyphe (version 5.3 for both modules). Three different sediment transport formulae were tested: (1) Engelund and Hansen (A monograph on sediment transport in alluvial streams, 3rd edn. Technological University of Denmark, Copenhagen, 1967) including the modifications proposed by Chollet and Cunge (J Hydraul Eng 17(1):1-13, 1979); (2) Bijker (Mechanics of sediment transport by the combination of waves and current. In: Design and reliability of coastal structures. 23rd international conference on Coastal Engineering, pp 147-173, 1968) and (3) Soulsby (Dynamics of Marine Sands. A manual for practical applications. HR Wallingford, Wallingford, p 142, 1997) modified version of van Rijn [J Hydraul Eng 110(10):1431-1456, 1984a, J Hydraul Eng 110(11):1613-1641, 1984b] formulation. Both a qualitative (i.e. visual comparison) and a quantitative tool [Brier Skill Score (BSS); described in Sutherland et al. in Coast Eng 51:917-939, 2004b] are applied to assess the similarity of simulations when compared to model predictions and observations. Tests confirmed the reliability and time efficiency of the ensemble technique, since it reproduced very well the results of a reference run, a computation based on the observed boundary conditions. For the spring-neap cycle modelled, the BSS was of 0.91 (a perfect modelling would have a BSS of 1), with a reduction in the simulation time on the order of 80%. For the 6-month-period simulation, results were also excellent: BSS=0.92 and a computer time reduction of 85%. In principle, this method has the advantage of being applied to any process-based numerical model.

Bernardes, Marcos E. C.; Davidson, Mark A.; Dyer, Keith R.; George, Ken J.

2006-07-01

110

Country-wide assessment of estuary health: An approach for integrating pressures and ecosystem response in a data limited environment  

NASA Astrophysics Data System (ADS)

Population and development pressures increase the need for proactive strategic management on a regional or country-wide scale - reactively protecting ecosystems on an estuary-by-estuary basis against multiple pressures is 'resource hungry' and not feasible. Proactive management requires a strategic assessment of health so that the most suitable return on investment can be made. A country-wide assessment of the nearly 300 functional South African estuaries examined both key pressures (freshwater inflow modification, water quality, artificial breaching of temporarily open/closed systems, habitat modification and exploitation of living resources) and health state. The method used to assess the type and level of the different pressures, as well as the ecological health status of a large number of estuaries in a data limited environment is described in this paper. Key pressures and the ecological condition of estuaries on a national scale are summarised. The template may also be used to provide guidance to coastal researchers attempting to inform management in other developing countries. The assessment was primarily aimed at decision makers both inside and outside the biodiversity sector. A key starting point was to delineate spatially the estuary functional zone (area) for every system. In addition, available data on pressures impacting estuaries on a national scale were collated. A desktop national health assessment, based on an Estuarine Health Index developed for South African ecological water requirement studies, was then applied systematically. National experts, all familiar with the index evaluated the estuaries in their region. Individual estuarine health assessment scores were then translated into health categories that reflect the overall status of South Africa's estuaries. The results showed that estuaries in the warm-temperate biogeographical zone are healthier than those in the cool-temperate and subtropical zones, largely reflecting the country's demographics and developmental pressures. A major finding was that, while a large number of South Africa's estuaries are still in an excellent to good condition, they tend to represent very small systems (<150 ha in size) in rural areas with few pressures. Larger systems, which are more important as nursery grounds because of their size, and also of higher economic and ecological importance, are in a fair to poor condition. This was due to pressures within the catchments influencing these downstream systems, and degradation as a result of direct development within the estuary functional zone.

Van Niekerk, L.; Adams, J. B.; Bate, G. C.; Forbes, A. T.; Forbes, N. T.; Huizinga, P.; Lamberth, S. J.; MacKay, C. F.; Petersen, C.; Taljaard, S.; Weerts, S. P.; Whitfield, A. K.; Wooldridge, T. H.

2013-09-01

111

NEW HAMPSHIRE'S ESTUARIES, THE STATE OF  

EPA Science Inventory

The State of the New Hampshire Estuary Report describes the region's valuable natural resources, explains how natural resources are linked to the cultural and economic well being of New Hampshire, and identifies threats to these resources. This State of the Estuaries Report summa...

112

Estuaries: Where Rivers Meet the Sea  

NSDL National Science Digital Library

This website is the educational site for NOAA's National Estuarine Research Reserve System (NERRS), managed and maintained by NERRS education staff. This site provides, primarily, an avenue for elementary, middle and high school students, and their teachers, to learn more about estuaries, research, and explore NOAAâs âliving laboratoriesâ - the National Estuarine Research Reserves. The Estuary Video Gallery offers a collection of short video clips. The main content themes include relationships between estuaries and humans, life in an estuary, impacts of society upon estuaries and current research and equipment used in monitoring estuaries in video format. Also included are E-Live Backpacks designed to extend and enhance specific Estuaries 101 High-School Curriculum activities by using video clips from our Video Gallery, and relating them to important estuary principles and concepts. Students are asked to review the materials in the E-Live Backpacks, to construct their own compelling questions, actively research those questions, and share their learning through final products. By going through these steps, you will lead students through a project-based learning experience. this site is also available in Spanish.

113

United States Air Force 611th Air Support Group/Civil Engineering Squadron Elmendorf AFB, Alaska. Remedial investigation and feasibility study. Bullen Point Radar Installation, Alaska. Final report  

SciTech Connect

The United States Air Force (Air Force) has prepared this Remedial investigation/Feasibility Study (RI/FS) report as part of the Installation Restoration Program (IRP) to present results of RI/FS activities at five sites at the Bullen Point radar installation. The IRP provides for investigating, quantifying, and remediating environmental contamination from past waste management activities at Air Force installations throughout the United States.

Karmi, S.

1996-03-18

114

Numerical modelling of morphodynamics—Vilaine Estuary  

NASA Astrophysics Data System (ADS)

The main objective of this paper is to develop a method to simulate long-term morphodynamics of estuaries dominated by fine sediments, which are subject to both tidal flow and meteorologically induced variations in freshwater run-off and wave conditions. The method is tested on the Vilaine Estuary located in South Brittany, France. The estuary is subject to a meso-macrotidal regime. The semi-diurnal tidal range varies from around 2.5 to 5 m at neap and spring, respectively. The freshwater input is controlled by a dam located approximately 8 km from the mouth of the estuary. Sediments are characterised as mostly fines, but more sandy areas are also found. The morphology of the estuary is highly influenced by the dam. It is very dynamic and changes in a complicated manner with the run-off from the dam, the tide and the wave forcing at the mouth of the estuary. Extensive hydrodynamic and sediment field data have been collected in the past and provide a solid scientific basis for studying the estuary. Based on a conceptual understanding of the morphodynamics, a numerical morphological model with coupled hydrodynamic, surface wave and sediment transport models is formulated. The numerical models are calibrated to reproduce sediment concentrations, tidal flat altimetry and overall sediment fluxes. Scaling factors are applied to a reference year to form quasi-realistic hydrodynamic forcing and river run-off, which allow for the simulations to be extended to other years. The simulation results are compared with observed bathymetric changes in the estuary during the period 1998-2005. The models and scaling factors are applied to predict the morphological development over a time scale of up to 10 years. The influence of the initial conditions and the sequence of external hydrodynamic forcing, with respect to the morphodynamic response of the estuary, are discussed.

Vested, Hans Jacob; Tessier, Caroline; Christensen, Bo Brahtz; Goubert, Evelyne

2013-04-01

115

Mercury sources and transformations in a man-perturbed tidal estuary: The Sinnamary Estuary, French Guiana  

Microsoft Academic Search

The distribution, partition and speciation of mercury (Hg) were studied along the redox gradient of an anthropogenically perturbed tropical estuary, the Sinnamary Estuary in French Guiana. This system is a partially mixed estuary characterized by an anoxic freshwater end-member, while the marine end-member consists of the Amazon Plume.The set up of an artificial oxygenation system in the anoxic freshwater end-member

B. Muresan; D. Cossa; M. Coquery; S. Richard

2008-01-01

116

Nitrogen, Phosphorus, and Suspended Solids Concentrations in Tributaries to the Great Bay Estuary Watershed in 2011.  

National Technical Information Service (NTIS)

Nitrogen, phosphorus, and sediment loads to the Great Bay Estuary are a growing concern. The Piscataqua Region Estuaries Partnership (PREP) calculates the nitrogen load from tributaries to the Great Bay Estuary for its State of the Estuaries reports. Ther...

M. A. Wood, P. Trowbridge

2012-01-01

117

Assessing the susceptibility of two UK estuaries to nutrient enrichment  

NASA Astrophysics Data System (ADS)

The susceptibility of two UK estuaries, the Severn and Solva Estuaries to the risks and impacts of nutrient enrichment was investigated in this study by examining nutrients, dissolved oxygen (DO) and turbidity concentrations in the estuaries and applying a risk assessment model based on the UK's Comprehensive Studies Task Team (CSTT) modelling approach. Both estuaries were found to be nutrient enriched. However, there was no evidence of oxygen depletion in the Severn and algal blooms were not observed due to high turbidity, strong tidal currents and tidally induced vertical mixing conditions in the estuary. Although algal blooms were observed in the Solva Estuary, the estuary was well-oxygenated due to the relatively high water exchange rate and consistent rapid flushing in the estuary. The conditions in the Solva Estuary were predicted to be favourable for phytoplankton productivity and the wider potential implications for future water quality protection strategies in the Solva were discussed.

Kadiri, Margaret; Bockelmann-Evans, Bettina; Rauen, William B.

2014-10-01

118

United States Air Force 611th Air Support Group Civil Engineering Squadron, Elmendorf AFB, Alaska. Remedial investigation and feasibility study Point Lay Radar Installation, Alaska. Final report  

SciTech Connect

The United States Air Force (Air Force) has prepared this Remedial Investigation/Feasibility Study (RI/FS) report to present the results of RI/FS activities at four sites located at the Point Lay radar installation. The remedial investigation (RI) field activities were conducted at the Point Lay radar installation during the summer of 1993. The four sites at Point Lay were investigated because they were suspected of being contaminated with hazardous substances. RI activities were conducted using methods and procedures specified in the RI/FS Work Plan, Sampling and Analysis Plan (SAP), and Health and Safety Plan.

Karmi, S.

1996-03-04

119

Copper speciation in estuaries and coastal waters  

E-print Network

The goals of this dissertation are to better understand the sources and the Cu binding ability of ligands that control Cu toxicity in estuaries and harbors, where elevated Cu concentrations have caused documented toxic ...

Kogut, Megan Brook, 1972-

2002-01-01

120

EPA'S BENTHIC HABITAT DATA FOR YAQUINA ESTUARY  

EPA Science Inventory

Scientists at EPA's National Health and Environmental Effects Research Laboratory, Western Ecology Division (WED) have been studying seafloor (benthic) habitats in Yaquina estuary for several years. Those studies were conducted as parts of several research projects, including: e...

121

Environmental Effects of Hydraulic Dredging in Estuaries.  

National Technical Information Service (NTIS)

Hydraulic channel and shell dredging and open water spoil disposal have little significant immediate effect on water quality in Alabama estuaries. Almost all of the sediment discharged by dredges settles very rapidly and is transported by gravity along th...

E. B. May

1973-01-01

122

Water renewal timescales in the Scheldt Estuary  

NASA Astrophysics Data System (ADS)

Using the concepts of the Constituent-oriented Age and Residence time Theory (CART), we compute timescales related to the water renewal in the Scheldt Estuary (The Netherlands/Belgium). Three different timescales are used to better understand and characterize the dynamics of the estuary: the age of the renewing water, the residence time and the exposure time. The residence time is the time taken by a water parcel to leave the estuary for the first time while the exposure time is the total time spent by a water parcel in the estuary including re-entries. The age of a renewing water parcel is defined as the time elapsed since it entered the estuary. The renewing water was split into three types: the water originating from the sea, the water originating from the upstream fresh tidal rivers and the water originating from the different canals and docks connected to the estuary. Every timescale is computed at any time and position by means of the finite-element, unstructured-mesh model SLIM. This results in movies of the timescale fields (shown as Supplementary material), allowing a detailed analysis of their spatial and temporal variabilities. The effect of the M2 tide and the discharge regime (winter, summer or average situation) on the timescales is also investigated. Tidally-averaged timescales vary little over the width of the estuary and hence exhibit a virtually one-dimensional behaviour. However, around these average values, the timescales can vary hugely over a tidal cycle, with amplitudes that significantly depend on the space coordinates. The reason thereof has yet to be elucidated. These results underscore the need for two- or three-dimensional models with high temporal resolution for investigating the dynamics of the Scheldt Estuary.

de Brye, Benjamin; de Brauwere, Anouk; Gourgue, Olivier; Delhez, Eric J. M.; Deleersnijder, Eric

2012-06-01

123

Iodine speciation in the Nile River estuary  

Microsoft Academic Search

During high- and low-flood periods, surface and bottom water samples were collected along the Nile River estuary for the voltammetric determination of dissolved iodine species. Iodine occurs in the estuary as iodate, iodide and organic iodine. Total iodine increases with salinity, showing a source feature in surface and bottom waters during high-flow indicating iodine input. During low-flow, total iodine showed

M. A. R Abdel-Moati

1999-01-01

124

Estuaries.  

ERIC Educational Resources Information Center

This publication is designed for use in standard science curricula to develop oceanologic manifestations of certain science topics. Included are teacher guides, student activities, and demonstrations designed to impart ocean understanding to high school students. When the student has completed this unit, he should be able to: (1) define an…

Awkerman, Gary L.

125

Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2005  

SciTech Connect

This report is the second annual report of a six-year project to evaluate the cumulative effects of habitat restoration projects in the Columbia River Estuary, conducted by Pacific Northwest National Laboratory's Marine Sciences Laboratory, NOAA's National Marine Fisheries Service Pt. Adams Biological Field Station, and the Columbia River Estuary Study Taskforce for the US Army Corps of Engineers. In 2005, baseline data were collected on two restoration sites and two associated reference sites in the Columbia River estuary. The sites represent two habitat types of the estuary--brackish marsh and freshwater swamp--that have sustained substantial losses in area and that may play important roles for salmonids. Baseline data collected included vegetation and elevation surveys, above and below-ground biomass, water depth and temperature, nutrient flux, fish species composition, and channel geometry. Following baseline data collection, three kinds of restoration actions for hydrological reconnection were implemented in several locations on the sites: tidegate replacements (2) at Vera Slough, near the city of Astoria in Oregon State, and culvert replacements (2) and dike breaches (3) at Kandoll Farm in the Grays River watershed in Washington State. Limited post-restoration data were collected: photo points, nutrient flux, water depth and temperature, and channel cross-sections. In subsequent work, this and additional post-restoration data will be used in conjunction with data from other sites to estimate net effects of hydrological reconnection restoration projects throughout the estuary. This project is establishing methods for evaluating the effectiveness of individual projects and a framework for assessing estuary-wide cumulative effects including a protocol manual for monitoring restoration and reference sites.

Diefenderfer, Heida L.; Thom, Ronald M.; Borde, Amy B.; Roegner, G. C.; Whiting, Allan H.; Johnson, Gary E.; Dawley, Earl; Skalski, John R.; Vavrinec, John; Ebberts, Blaine D.

2006-12-20

126

Simulating Suspended Silt Concentrations in the Ems Estuary, The Netherlands  

NASA Astrophysics Data System (ADS)

1 Introduction The Ems Estuary is situated in the North-east Netherlands on the border with Germany. Its area, including the tidal river and excluding the outer delta, is ± 500 km2. The area of the outer delta is ± 100 km2. The length of the estuary from the inlet to the town of Leer in Germany is approximately 75 km. The mean tidal range varies over years (de Jonge, 1992), but is approximately 2.3 m near the island of Borkum (tidal inlet) and approximately 3.2 m near the town of Emden in Germany. The estuary receives water from the rain-fed River Ems (approximately 115 m3/s on average). A second much smaller freshwater input emanates from the small canalized river Westerwoldsche Aa (12.5 m3/s on average). These discharges vary strongly within and between years. The result of the interaction between freshwater discharge and seawater brought in by the tide is a salinity gradient, the length and position of which is strongly dependent on the water discharge by the rivers. The present morphology of the estuary is the result of natural processes such as tidal currents, wind and wave driven currents and river discharge, resulting in sediment trans-port and sedimentation and erosion patterns. These natural processes are affected by human interferences like maintenance dredging of the navigation channels, land reclamation, building of dikes, etc. The greatest changes in the last 50 years in the physical functioning of the Ems estuary have been the increased sea level and tidal range, the increased amplitude and frequency of storm surge, and greatly increased turbidity and sediment concentrations (particularly near the estuarine turbidity maximum). Much of the changes can be traced directly or indirectly to anthropogenic influence. 2 Aim and approach We studied the hydrodynamics and morphodynamics of the Ems estuary. One of the aims was to gain more insight in the behaviour of the suspended silt concentrations in the estuary and the anthropogenic influence thereon. We applied a beta release of the state-of-the-art Delft3D numerical model for this purpose. The model includes a new sediment transport module published by Van Rijn (2007, 2007a). The vertical distribution of the suspended sediment concentration in the transport module depends on the effective settling velocity of the sediment, the bed shear velocity and the turbulence. The silt transport is simulated every time step together with the flow (online), which means that the impact of the calculated concentration is accounted for in the hydrodynamics. Major challenge was to accurately simulate the relatively high suspended silt concentrations observed near the estuarine turbidity maximum. 3 Results The paper will compare observed and predicted water levels, salinity distributions and suspended silt concentrations. Figure 1 shows an example of predicted depth-averaged suspended silt concentrations during spring high tide without waves. Under these conditions the depth-averaged concentrations decrease from about 2 kg/m3 in the Unterems (upstream of Emden) to almost zero seaward of Borkum. PIC Figure 1: Figure 2 Observed and predicted salinities in the upper part of the water column along the estuary The presence of waves will increase the concentrations on the shoals but have a limited effect on the concentrations in the channels. Figure 2 presents observed and predicted salinities along the estuary. The model results encouragingly agree with the observations. PIC 4 References De Jonge, V.N., 1992. Tidal flow and residual flow in the Ems estuary. Estuarine, Coastal and Shelf Science, 34: 1-22. Van Rijn, L.C., 2007. Unified View of Sediment Transport by Currents and Waves. I: Initiation of Motion, Bed Roughness, and Bed-Load Transport. Journal of Hydraulic Engineering, 133(6): 649-667. Van Rijn, L.C., 2007a. Unified View of Sediment Transport by Currents and Waves. II: Suspended Transport. Journal of Hydraulic Engineering, 133(6): 668-689.

Grasmeijer, B. T.

2009-04-01

127

MOBILE BAY NATIONAL ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN  

EPA Science Inventory

In simplest terms, an estuary is defined as an area where rivers meet the sea. They are transitional zones where freshwater rivers meet tidally influenced marine waters. Estuaries are considered environmentally and economically important because of their exceptional biological di...

128

Remedial investigation/feasibility study Work Plan and addenda for Operable Unit 4-12: Central Facilities Area Landfills II and III at the Idaho National Engineering Laboratory  

SciTech Connect

This document is divided into two main sections -- the Work Plan and the addenda. The Work Plan describes the regulatory history and physical setting of Operable Unit 4-12, previous sampling activities, and data. It also identifies a preliminary conceptual model, preliminary remedial action alternatives, and preliminary applicable or relevant and appropriate requirements. In addition, the Work Plan discusses data gaps and data quality objectives for proposed remedial investigation activities. Also included are tasks identified for the remedial investigation/feasibility study (RI/FS) and a schedule of RI/FS activities. The addenda include details of the proposed field activities (Field Sampling Plan), anticipated quality assurance activities (Quality Assurance Project Plan), policies and procedures to protect RI/FS workers and the environment during field investigations (Health and Safety Plan), and policies, procedures, and activities that the Department of Energy will use to involve the public in the decision-making process concerning CFA Landfills II and III RI/FS activities (Community Relations Plan).

Keck, K.N.; Stormberg, G.J.; Porro, I.; Sondrup, A.J.; McCormick, S.H.

1993-07-01

129

Multi-Scale Action Effectiveness Research in the Lower Columbia River and Estuary, 2012  

SciTech Connect

The study reported herein was conducted for the U.S. Army Corps of Engineers, Portland District (USACE) by researchers at the Pacific Northwest National Laboratory (PNNL), Oregon Department of Fish and Wildlife (ODFW), National Marine Fisheries Service (NMFS), University of Washington (UW), and U.S. Fish and Wildlife Service (USFWS). The goal of the study was to evaluate the ecological benefits of restoration actions for juvenile salmon in the lower Columbia River and estuary (LCRE; rkm 0–234).

Johnson, Gary E.; Sather, Nichole K.; Storch, Adam; Johnson, Jeff; Skalski, J. R.; Teel, D. J.; Brewer, Taylor; Bryson, Amanda J.; Dawley, Earl M.; Kuligowski, D. R.; Whitesel, T.; Mallette, Christine

2013-11-30

130

Evaluation of Cumulative Ecosystem Response to Restoration Projects in the Lower Columbia River and Estuary, 2010  

SciTech Connect

This is the seventh and final annual report of a project (2004–2010) addressing evaluation of the cumulative effects of habitat restoration actions in the 235-km-long lower Columbia River and estuary. The project, called the Cumulative Effects (CE) study, was conducted for the U.S. Army Corps of Engineers Portland District by a collaboration of research agencies led by the Pacific Northwest National Laboratory. We achieved the primary goal of the CE study to develop a methodology to evaluate the cumulative effects of habitat actions in the Columbia Estuary Ecosystem Restoration Program. We delivered 1) standard monitoring protocols and methods to prioritize monitoring activities; 2) the theoretical and empirical basis for a CE methodology using levels-of-evidence; 3) evaluations of cumulative effects using ecological relationships, geo-referenced data, hydrodynamic modeling, and meta-analyses; and 4) an adaptive management process to coordinate and coalesce restoration efforts in the LCRE. A solid foundation has been laid for future comprehensive evaluations of progress made by the Columbia Estuary Ecosystem Restoration Program to understand, conserve, and restore ecosystems in the lower Columbia River and estuary.

Johnson, Gary E.; Diefenderfer, Heida L.; Thom, Ronald M.; Roegner, G. Curtis; Ebberts, Blaine D.; Skalski, John R.; Borde, Amy B.; Dawley, Earl; Coleman, Andre M.; Woodruff, Dana L.; Breithaupt, Stephen A.; Cameron, April; Corbett, C.; Donley, Erin E.; Jay, D. A.; Ke, Yinghai; Leffler, K.; McNeil, C.; Studebaker, Cindy; Tagestad, Jerry D.

2012-05-01

131

Engineering Engineering  

E-print Network

-solving skills engineers and engineering technologist need, but also the "people" skills (teamwork, communication" skills (teamwork, communication, and leadership) necessary for success in your future career. We look

Maroncelli, Mark

132

SAN FRANCISCO ESTUARY PROJECT COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN  

EPA Science Inventory

The Estuary, a significant natural resource, San Francisco Bay and the Delta combine to form the West Coast's largest estuary. The Estuary conveys the waters of the Sacramento and San Joaquin Rivers to the Pacific Ocean. It encompasses roughly 1,600 square miles, drains over 40 p...

133

THE ATLANTIC STURGEON, ACIPENSER OXYRHYNCHUS, IN THE DELAWARE RIVER ESTUARY  

E-print Network

summer. This seasonal distribution appeared similar to that described for the Hudson River estuaryTHE ATLANTIC STURGEON, ACIPENSER OXYRHYNCHUS, IN THE DELAWARE RIVER ESTUARY HAROLD M. BRUNDAGE III River estuary from 1958 through 1980 were obtained from the literature, unpublished data, and logs

134

Seasonal variation of sediment deposition in the Hudson River estuary  

Microsoft Academic Search

During and following the spring freshet, rapid rates of sediment deposition were observed in the Hudson River estuary. Side-scan sonar surveys and sediment coring studies revealed a large amount of spatial variability in sedimentation within the estuary and a distinct seasonal progression. During the freshet, sediment was deposited in the seaward reaches of the estuary. In the two-month period after

Jonathan D Woodruff; W. Rockwell Geyer; Christopher K Sommerfield; Neal W Driscoll

2001-01-01

135

Monitoring and Managing Contamination in the San Francisco Estuary 199399  

E-print Network

on Estuary management contributed by the staff of the San Francisco Bay Regional Water Quality Control Board (Regional Board). BAY VS. ESTUARY Although most people still refer to the expanse of water inside the Golden indicate that the San Francisco Estuary is moderately contami- nated. Although levels of many contaminants

136

The Estuary Guide. Level 3: High School. Draft.  

ERIC Educational Resources Information Center

Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the high school level seeks to teach what estuaries are; provide opportunities to practice decision-making that affects estuaries; and encourage students to…

Alexander, Glen; And Others

137

ENGINEERING FEASIBILITY AND ECONOMICS OF CO2 SEQUESTRATION/USE ON AN EXISTING COAL-FIRED POWER PLANT: A LITERATURE REVIEW  

SciTech Connect

The overall objective of this study is to evaluate the technical feasibility and the economics of alternate CO{sub 2} capture and sequestration/use technologies for retrofitting an existing pulverized coal-fired power plant. To accomplish this objective three alternative CO{sub 2} capture and sequestration systems will be evaluated to identify their impact on an existing boiler, associated boiler auxiliary components, overall plant operation and performance and power plant cost, including the cost of electricity. The three retrofit technologies that will be evaluated are as follows: (1) Coal combustion in air, followed by CO{sub 2} separation from flue gas with Kerr-McGee/ABB Lummus Global's commercial MEA-based absorption/stripping process. (2) Coal combustion in an O{sub 2}/CO{sub 2} environment with CO{sub 2} recycle. (3) Coal combustion in air with oxygen removal and CO{sub 2} captured by tertiary amines In support of this objective and execution of the evaluation of the three retrofit technologies a literature survey was conducted. It is presented in an ''annotated'' form, consistent with the following five sections: (1) Coal Combustion in O{sub 2}/CO{sub 2} Media; (2) Oxygen Separation Technologies; (3) Post Combustion CO{sub 2} Separation Technologies; (4) Potential Utilization of CO{sub 2}; and (5) CO{sub 2} Sequestration. The objective of the literature search was to determine if the three retrofit technologies proposed for this project continue to be sound choices. Additionally, a review of the literature would afford the opportunity to determine if other researchers have made significant progress in developing similar process technologies and, in that context, to revisit the current state-of-the-art. Results from this literature survey are summarized in the report.

Carl R. Bozzuto; Nsakala ya Nsakala

2000-01-31

138

Nutrient transports in a Swedish estuary  

NASA Astrophysics Data System (ADS)

Himmerfjärd is a Swedish estuary bordering on the Baltic. The estuary lacks astronomical tides and its circulation is driven by winds and freshwater runoff. Because of a tertiary sewage treatment plant located at its inner end, the estuary is becoming increasingly eutrophic. A field study was carried out for a 78-day period in late summer and early fall of 1977 to determine rates of nutrient transport and to construct nutrient budgets. Since physical parameters (current velocity, temperature, salinity, winds and water level changes) were measured more frequently than nutrients (phosphate, nitrate, nitrite and ammonium) it was necessary to develop a suitable method to calculate nutrient flux time series and net nutrient fluxes. Over the study period, Himmerfjärd imported phosphorus and exported nitrogen. Direction of nutrient fluxes and changes in flux direction were consistent with the structure of the baroclinic currents.

Wilmot, Wayne; Toll, Peter; Kjerfve, Björn

1985-08-01

139

Stratigraphic Evidence of Eutrophication in an Estuary  

NASA Astrophysics Data System (ADS)

Vertical changes in chlorophyll degradation products preserved in sediments deposited in an urban estuary show a significant increase in algal productivity with the introduction of sewage effluent into the river. By comparison, algal production during intensive agriculture of the watershed, including heavy applications of fertilizers, was less by an order of magnitude where there was no sewage discharge from a point source. Concentrations of orthophosphorus correspond with concentrations of algal cells and chlorophyll in the water column and are greater by an order of magnitude where sewage is discharged into an estuary draining an urban-agricultural watershed than where there is no sewage. The response of the estuary to short- and long-term changes in the amount of sewage discharged is reflected by similar changes in chlorophyll production. However, chlorophyll production does not correspond with increases in the amount of fertilizers used in recent years over the amount used in the middle to late nineteenth century.

Brush, Grace S.

1984-05-01

140

Modeling tidal distortion in the Ogeechee Estuary  

NASA Astrophysics Data System (ADS)

A 3D numerical model is used to simulate the distortion of tidal hydrodynamics in the Ogeechee Estuary, GA. The Ogeechee, like many estuaries found in the Southeastern US, consists of shallow channel networks and extensive intertidal storage in the form of wetlands. Such features are known to induce non-linear overtide generation and significant tidal distortion, otherwise known as tidal stage asymmetry. Simulations are run with varying parameters to assess their effects on modeling tidal distortion for the Ogeechee Estuary: bottom friction coefficients, enhanced wetland friction coefficients, and tidal flat elevations. To succinctly quantify the degree of distortion across the domain, the statistical parameters of skewness and asymmetry are calculated for time series of water surface heights and channel volume fluxes. The intertidal storage causes the peak flood flux to occur later and the peak ebb flux to occur earlier, thereby resulting in positive asymmetry for the volume flux for the full estuary. However, ebb dominance is a localized feature and varies throughout the estuary. Increasing the intertidal storage by lowering wetland elevation enhances the effects on high tide and volume flux magnitudes, decreasing the ebb-dominance and volume flux asymmetry typically associated with intertidal storage thereby indicating the importance of the wetland elevation over the total storage volume. Increased channel bottom friction reduces ebb-dominance by extending the duration of the falling tide. More interestingly, increased wetland friction reduces the influence of wetland intertidal storage on tidal distortion. The model suggests an increase in wetland friction does little to dampen wave propagation at high tide but rather impedes the lateral flooding of wetlands, reducing ebb dominance. Tidal flat elevation has the largest impact on distortion for the Ogeechee Estuary whereas enhanced wetland and bottom frictional influences on distortion are small, albeit not insignificant.

Bruder, Brittany; Bomminayuni, Sandeep; Haas, Kevin; Stoesser, Thorsten

2014-10-01

141

Facilitation of the Estuary/Ocean Subgroup and the Expert Regional Technical Group, Fiscal Year 2013 Annual Report  

SciTech Connect

This project covers facilitation of the Estuary/Ocean Subgroup (EOS) for federal research, monitoring, and evaluation (RME) and the Expert Regional Technical Group (ERTG) for estuary habitat restoration. The EOS is part of the research, monitoring, and evaluation effort that the Action Agencies (Bonneville Power Administration [BPA], U.S. Army Corps of Engineers [Corps], U.S. Bureau of Reclamation) developed in response to obligations arising from the Endangered Species Act as applied to operation of the Federal Columbia River Power System (FCRPS). The EOS is tasked by National Marine Fisheries Service (NMFS) and the Action Agencies (AAs) to design and coordinate implementation of the federal RME plan for the lower Columbia River and estuary, including the river’s plume in the ocean. Initiated in 2002, the EOS is composed of members from BPA, the Corps, NMFS, and Pacific Northwest National Laboratory’s (PNNL’s) Marine Sciences Laboratory, and other agencies as necessary.

Johnson, Gary E.; Sather, Nichole K.

2013-10-30

142

Ciliated Protozoa of the polluted Tees estuary  

NASA Astrophysics Data System (ADS)

In a study of the ciliated Protozoa of Bran Sand, a sheltered beach in the Tees estuary, 20 putative species were identified. This beach was richer in species than the nearby North Gare beach. In experimental batch cultures, seawater from the estuary had an inhibitory effect upon growth of a strain of Uronema marinum Dujardin which was isolated from an unpolluted beach at Robin Hood's Bay. The tolerance to metals of a Tees strain of U. marinum was assessed in simple toxicity tests; lethal levels for this strain were found to be similar to those reported elsewhere for the Robin Hood's Bay strain.

Parker, James G.

1981-03-01

143

San Francisco Estuary: Invasive Spartina Project  

NSDL National Science Digital Library

The Invasive Spartina Project was developed by the California State Coastal Conservancy to determine the extent and address the problem of invasive Spartina in the San Francisco Estuary. This Web site describes the efforts of the Invasive Spartina Project and the risk that Spartina poses. A variety of maps and photos are used to describe the results of the 2000-2001 survey of Spartina populations within the estuary. A host of other documents regarding Spartina and this project are also available in Adobe Acrobat (.pdf) format.

2002-01-01

144

Detection of estuarine and tidal river hydromorphology using hyper-spectral and LiDAR data: Forth estuary, Scotland  

NASA Astrophysics Data System (ADS)

High spatial resolution hyper-spectral imagery (CASI) and light detection and ranging (LiDAR) imagery acquired for the tidal River Carron and Forth estuary, Scotland, were used in conjunction with field surveys to assess the feasibility of monitoring hydromorphology and human alterations with satellite and airborne remote sensing data. The study was undertaken in the context of the European Union Water Framework Directive (WFD) that requires member states to monitor hydromorphological elements as a component of the ecological status of rivers, estuaries and shorelines. Visual assessment and automated classifications of the imagery were compared with field survey data for an estuarine reach comprising saline waters, mudflats, a tidal reach of a tributary river and an urban/industrialised shoreline. The morphology of the estuary and inflowing tidal waters together with most artificial features of interest could be clearly seen in the CASI imagery at 1 m spatial resolution. Supervised classification of the imagery produced an overall accuracy value of 72%. Downgrading the imagery to simulate the spatial resolution of 4 m IKONOS satellite data surprisingly improved the accuracy to 74%. Simulation of 10 m SPOT imagery resulted in an image where many artificial features of interest such as roads, pipelines and jetties were rendered invisible. Adding LiDAR data as an additional data set aided manual and automated identification of features and visualisation of the hydromorphology of the rivers and estuaries in the study area. Shadows cast from tall objects were a feature of the winter imagery and reduced automated classification accuracy. Overall, the study demonstrates that high spatial resolution remotely sensed digital imagery has the potential to be a useful tool for panoptic mapping of the geomorphology and human impact on tidal rivers and estuaries. In the context of the WFD, remote sensing provides a potential way forward for monitoring the physical status of rivers and estuaries at the national scale. The possibilities and constraints, in light of the findings of this study, are discussed.

Gilvear, David; Tyler, Andrew; Davids, Corine

2004-11-01

145

BATHYMETRY FOR ALBEMARLE AND PAMLICO ESTUARIES, NC  

EPA Science Inventory

Bathymetry for the Albemarle and Pamlico Estuaries obtained from National Oceanographic and Atmospheric Administration-National Ocean Service (NOAA-NOS). See the metadata within the files from NOAA-NOS for more details and warnings concerning merging with US Geolgoical Survey Dig...

146

Listening to Estuary English in Singapore  

ERIC Educational Resources Information Center

In Singapore, many people are not familiar with Estuary English (EE), the variety of English becoming popular in much of southern England. In the current study, when students listened to interviews with EE speakers and were asked to transcribe orthographically what they heard, most of them had severe problems. Features of pronunciation that…

Deterding, David

2005-01-01

147

INDICATORS OF ECOSYSTEM INTEGRITY FOR ESTUARIES  

EPA Science Inventory

Jordan, Stephen J. and Lisa M. Smith. In press. Indicators of Ecosystem Integrity for Estuaries. In: Proceedings of the Estuarine Indicators Workshop, 29-31 October 2003, Sanibel Island, FL. Sanibel-Captiva Conservation Foundation, Sanibel, FL. 23 p. (ERL,GB 1194). Ideal ...

148

Vegetation of the Elwha River Estuary  

E-print Network

, 2011, chapter 4, this report). Removal of the two dams upstream on the Elwha River, anticipated be compared, following the impending removal of Glines Canyon and Elwha Dams upstream on the Elwha River. DamChapter 8 8 Chapter Vegetation of the Elwha River Estuary By Patrick B. Shafroth, Tracy L. Fuentes

149

San Francisco Estuary Institute 7770 Pardee Road  

E-print Network

San Francisco Estuary Institute 7770 Pardee Road Oakland, CA 94621 (510) 746­7334 www Drawbridge (Courtesy of UCB and UCSB) 1857 Near the mouth of Alameda Creek 1896 Development of modern salt the origin of many of the early Euro-American salt pond complexes. Management for salt production most likely

150

Climate change and its impacts on estuaries  

EPA Science Inventory

Past, present, and future research by WED scientists in the TEP region will be described to lay the foundation for examination of potential climate change effects on estuaries and the broader coastal zone in the Pacific Northwest (PNW). Results from National Coastal Assessments,...

151

Tracing kepone contamination in James estuary sediments  

SciTech Connect

The escape of Kepone into the James River estuary, Virginia, for more than nine years produced widespread contamination of the sediments with important ecological consequences. The pollutant extended seaward more than 100 km from its source and contaminated an estimated 31 million tonnes of sediment to depths of more than 60 cm. Kepone spread through the food chain and to every segment of the environment from marshes to the channel floor. Kepone escaped mainly during high river inflow from a point source in freshwater tributaries. Near the source Kepone is associated with organic material but in the lower estuary it is adsorbed on finegrained sediment. A bulk of the contaminated sediment is transported and trapped by the estuarne circulation. It accumulates in the turbidity maximum of the middle estuary far from the source. In this zone it is deposited in less energetic sites where sedimentation is relatively fast. Contamination extends downward > 60 cm; peak concentrations at 10 to 25 cm relate to high production in 1974. The Kepone inventory is now being buried by less contaminated sediment. Recovery is most rapid in the middle estuary where contamination was most intense.

Nichols, M.M. (Virginia Inst. of Marine Sciences, Gloucester Point); Cutshall, N.H.

1981-01-01

152

Yeast community survey in the Tagus estuary  

Microsoft Academic Search

The yeast community in the waters of the Tagus estuary, Portugal, was followed for over a year in order to assess its dynamics. Yeast occurrence and incidence were measured and this information was related to relevant environmental data. Yeast occurrence did not seem to depend upon tides, but river discharge had a dramatic impact both on the density and diversity

João M. G. C. F. de Almeida

2005-01-01

153

BCG Approaches for Improved Management of Estuaries  

EPA Science Inventory

Estuaries and other complex aquatic systems are exposed to a variety of stressors that act at several scales, but are managed piecemeal - - often resulting in a ?death by 1000 cuts? caused by cumulative impacts to these valued resources. To address this, managers need tools that...

154

MODELING FINE SEDIMENT TRANSPORT IN ESTUARIES  

EPA Science Inventory

A sediment transport model (SEDIMENT IIIA) was developed to assist in predicting the fate of chemical pollutants sorbed to cohesive sediments in rivers and estuaries. Laboratory experiments were conducted to upgrade an existing two-dimensional, depth-averaged, finite element, coh...

155

Estuaries and Tidal Marshes. Habitat Pac.  

ERIC Educational Resources Information Center

This educational packet consists of an overview, three lesson plans, student data sheets, and a poster. The overview examines estuaries and tidal or salt marshes by discussing the plants and animals in these habitats, marsh productivity, benefits and management of the habitats, historical aspects, and development and pollution. A glossary and list…

Fish and Wildlife Service (Dept. of Interior), Washington, DC.

156

Kaua'i: Streams and Estuaries.  

ERIC Educational Resources Information Center

Designed to help teachers develop students' awareness and understanding of some of Hawaii's endangered aquatic resources, this module contains activities and instructional suggestions for use with intermediate as well as high school students. The module is divided into two sections which explore the streams and estuaries of Kauai. Activities in…

Hawkins, John, Ed.; Murakami, Colleen, Ed.

157

Improving lakebed sediment quality in an urban estuary, Presque Isle Bay, Lake Erie, USA  

NASA Astrophysics Data System (ADS)

Presque Isle Bay, Lake Erie, is a microtidal freshwater estuary on the North American Great Lakes. It is one of 40 remaining environmental Areas of Concern (AoCs) on the Great Lakes that have one or more water, habitat, or sediment quality impairments as defined by the International Joint Commission. In-situ natural capping using sediment from to-be-remediated watersheds and other sources is being considered as the most feasible means of remediating contaminated sediments in the estuary. A multi-decade sediment budget shows that, when localized anthropogenic effects are accounted for, the estuary net-accumulated sediment over time from three major sources: the Lake Erie littoral system (20%), streams (25%), and bank erosion and bluff recession (41%). The non-stream sources supply environmentally clean sediment from ancient coastal deposits along the shoreline, and from the modern littoral system. However, organic and metallic contaminants are supplied by streams and run-off and remain a remediation challenge. From a geological perspective, natural capping of contaminated sediment over the next several decades is a viable solution for the majority of the bay. The mechanism may not work effectively in all areas because approximately 25% of the bay floor is moderately net- erosional or accumulates sediments very slowly.

Foyle, A. M.; Norton, K. P.

2007-12-01

158

Baseline ecological risk assessment of the Calcasieu Estuary, Louisiana: 1. Overview and problem formulation  

USGS Publications Warehouse

A remedial investigation/feasibility study (RI/FS) of the Calcasieu Estuary cooperative site was initiated in 1998. This site, which is located in the southwestern portion of Louisiana in the vicinity of Lake Charles, includes the portion of the estuary from the saltwater barrier on the Calcasieu River to Moss Lake. As part of the RI/FS, a baseline ecological risk assessment (BERA) was conducted to assess the risks to aquatic organisms and aquatic-dependent wildlife exposed to environmental contaminants. The purpose of the BERA was to determine if adverse effects on ecological receptors are occurring in the estuary; to evaluate the nature, severity, and areal extent of any such effects; and to identify the substances that are causing or substantially contributing to effects on ecological receptors. This article describes the environmental setting and site history, identifies the chemicals of potential concern, presents the exposure scenarios and conceptual model for the site, and summarizes the assessment and measurement endpoints that were used in the investigation. Two additional articles in this series describe the results of an evaluation of effects-based sediment-quality guidelines as well as an assessment of risks to benthic invertebrates associated with exposure to contaminated sediment.

MacDonald, Donald D.; Moore, Dwayne R.J.; Ingersoll, Christopher G.; Smorong, Dawn E.; Carr, R. Scott; Gouguet, Ron; Charters, David; Wilson, Duane; Harris, Tom; Rauscher, Jon; Roddy, Susan; Meyer, John

2011-01-01

159

A Hydrologic and Geomorphic Model of Estuary Breaching and Closure  

NASA Astrophysics Data System (ADS)

Many coastal estuaries are separated seasonally from the ocean by a swash-deposited beach berm. The opening of the inlet may occur by fluvial erosion of the beach berm and closure occurs when sand deposition outpaces erosion of the inlet. To better understand how the hydrology of estuaries affects breaching and closing patterns, a model is developed that incorporates an estuary hydrologic budget with a geormorphic model of the inlet system. When calibrated, the model is able to reproduce the initial seasonal breaching, seasonal closure, intermittent closures and breaches, and the low-streamflow estuary hydrology of the Carmel Lagoon, located in Central California. For two years when the estuary inlet drains directly across the beach-berm in accordance with model assumptions, the calibrated model predicts the observed 48-hour estuary stage amplitude with correlation coefficients of 0.77 and 0.65. For the calibrated model, streamflow is the predominant control on whether the estuary inlet is open or closed. In a series of sensitivity analyses, it is seen that the function of bar-built, coastal estuaries are sensitive to morphologic and hydrologic variations of the beach berm, and changes to the estuary storage itself. By varying individual components of the berm-system and estuary storage, the amount of the time the estuary is open changes -43 - 28% for the 18.2 model period. The morphology of the berm affects barrier groundwater flow, inlet hydraulics, and estuary storage. Importantly, the elevation of the berm determines the volume of water that must enter the estuary in order to breach, and it modulates the wave-overtopping flux. A high berm renders streamflow the predominant control on function and decreases the amount of time that the estuary is open by 4%, whereas a lower berm allows wave-overtopping to contribute to function and increases time open by 24%. By excavating an estuary, it will breach less frequently (-32% change in open) and store water up to 3 months later into the summer. Beach aquifer hydraulic conductivity significantly alters the amount of time the estuary is open or closed; a high hydraulic conductivity berm remains open 43% less than the calibrated model, but a decreased hydraulic conductivity causes only an 11% increase in time open. As a result of sea level rise of 1.67m by 2100, and a beach berm that remains in its current location and accretes vertically, the amount of time the estuary remains open may decrease up to 22%. Model results indicate that the amount of time the estuary is open is more sensitive to changes in wave run-up than the amount of sand deposited in the inlet per each overtopping wave.

Rich, A.; Keller, E. A.

2012-12-01

160

Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2006  

SciTech Connect

This report is the third annual report of a six-year project to evaluate the cumulative effects of habitat restoration action in the Columbia River Estuary (CRE). The project is being conducted for the U.S. Army Corps of Engineers (Corps) by the Marine Sciences Laboratory of the Pacific Northwest National Laboratory, the Pt. Adams Biological Field Station of the National Marine Fisheries Service, and the Columbia River Estuary Study Taskforce. Measurement of the cumulative effects of ecological restoration projects in the Columbia River estuary is a formidable task because of the size and complexity of the estuarine landscape and the meta-populations of salmonids in the Columbia River basin. Despite the challenges presented by this system, developing and implementing appropriate indicators and methods to measure cumulative effects is the best way to enable estuary managers to track the overall effectiveness of investments in estuarine restoration projects. This project is developing methods to quantify the cumulative effects of multiple restoration activities in the CRE. The overall objectives of the 2006 study were to continue to develop techniques to assess cumulative effects, refine the standard monitoring protocols, and initiate development of an adaptive management system for Corps of Engineers’ habitat restoration monitoring efforts in the CRE. (The adaptive management effort will be reported at a later date.) Field studies during 2006 were conducted in tidal freshwater at Kandoll Farm on the lower Grays River and tidal brackish water at Vera Slough on Youngs Bay. Within each of area, we sampled one natural reference site and one restoration site. We addressed the overall objectives with field work in 2006 that, coupled with previous field data, had specific objectives and resulted in some important findings that are summarized here by chapter in this report. Each chapter of the report contains data on particular monitored variables for pre- and post-restoration conditions at both the Kandoll and Vera study areas.

Johnson, Gary E.; Borde, Amy B.; Dawley, Earl; Diefenderfer, Heida L.; Ebberts, Blaine D.; Putman, Douglas A.; Roegner, G. C.; Thom, Ronald M.; Vavrinec, John; Whiting, Allan H.

2007-12-06

161

Haltenbanken gas trunkline technically feasible  

SciTech Connect

Installation of a large-diameter subsea gas pipeline over the irregular, iceberg-scoured seabed of the Haltenbanken field in the Norwegian North Sea is technically feasible. That's the conclusion of a major feasibility study of a gas trunkline from Haltenbanken offshore Norway to shore. The study further concludes that considerable cost savings could be obtained by careful routing of the pipeline within a sufficiently wide corridor. Characteristic features of the seabed area are water depths between 250-300 m (820-985 ft) and rugged seabed topography caused by frequent and highly irregular occurrence of iceberg ploughmarks and pockmarks. Crossing these areas with a gas trunkline represents a major pipeline engineering challenge. Outlined here are the strategy for assessing the final route selection, establishing free-span acceptance criteria, and selecting free-span correction methods.

Moshagen, H.; Gjertveit, E.; Rothaug, K.; Sveggen, O.

1988-05-23

162

77 FR 15722 - Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Management...  

Federal Register 2010, 2011, 2012, 2013

...Incidental to Specified Activities; Russian River Estuary Management Activities AGENCY...take marine mammals incidental to Russian River estuary management activities. Pursuant...conducted in management of the Russian River estuary in Sonoma County,...

2012-03-16

163

76 FR 8345 - Endangered and Threatened Species; Recovery Plan Module for Columbia River Estuary Salmon and...  

Federal Register 2010, 2011, 2012, 2013

...Species; Recovery Plan Module for Columbia River Estuary Salmon and Steelhead AGENCY: National...availability; recovery plan module for Columbia River estuary salmon and steelhead...announces the adoption of the Columbia River Estuary Endangered Species Act...

2011-02-14

164

78 FR 14985 - Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Management...  

Federal Register 2010, 2011, 2012, 2013

...Incidental to Specified Activities; Russian River Estuary Management Activities AGENCY...take marine mammals incidental to Russian River estuary management activities. Pursuant...conducted in management of the Russian River estuary in Sonoma County,...

2013-03-08

165

Estuaries. Estuaries are places where fresh and salt water mix. Typically they occur where rivers enter the sea. Estero Limantour, Drakes' Bay, Point Reyes National Seashore.  

E-print Network

Estuaries Lecture 18 #12;Estuaries. Estuaries are places where fresh and salt water mix. Typically than an equivalent volume of fresh water. If you go back to the graph of water density as a function and shallow, and river currents are often strong. Hence salt and fresh water are often mixed in estuaries

Richerson, Peter J.

166

A report published by the San Francisco Estuary Institute and the Regional Monitoring Program for Water Quality in the San Francisco Estuary  

E-print Network

and the Regional Monitoring Program for Water Quality in the San Francisco Estuary The Pulse of the Estuary Monitoring and Managing Water Quality in the San Francisco Estuary 35 Years After the Clean Water Act #12: Monitoring and Managing Water Quality in the San Francisco Estuary. SFEI Contribution 532. San Francisco

167

Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, Annual Report 2010  

SciTech Connect

This report describes the 2010 research conducted under the U.S. Army Corps of Engineers (USACE) project EST-P-09-1, titled Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, and known as the 'Salmon Benefits' study. The primary goal of the study is to establish scientific methods to quantify habitat restoration benefits to listed salmon and trout in the lower Columbia River and estuary (LCRE) in three required areas: habitat connectivity, early life history diversity, and survival (Figure ES.1). The general study approach was to first evaluate the state of the science regarding the ability to quantify benefits to listed salmon and trout from habitat restoration actions in the LCRE in the 2009 project year, and then, if feasible, in subsequent project years to develop quantitative indices of habitat connectivity, early life history diversity, and survival. Based on the 2009 literature review, the following definitions are used in this study. Habitat connectivity is defined as a landscape descriptor concerning the ability of organisms to move among habitat patches, including the spatial arrangement of habitats (structural connectivity) and how the perception and behavior of salmon affect the potential for movement among habitats (functional connectivity). Life history is defined as the combination of traits exhibited by an organism throughout its life cycle, and for the purposes of this investigation, a life history strategy refers to the body size and temporal patterns of estuarine usage exhibited by migrating juvenile salmon. Survival is defined as the probability of fish remaining alive over a defined amount of space and/or time. The objectives of the 4-year study are as follows: (1) develop and test a quantitative index of juvenile salmon habitat connectivity in the LCRE incorporating structural, functional, and hydrologic components; (2) develop and test a quantitative index of the early life history diversity of juvenile salmon in the LCRE; (3) assess and, if feasible, develop and test a quantitative index of the survival benefits of tidal wetland habitat restoration (hydrologic reconnection) in the LCRE; and (4) synthesize the results of investigations into the indices for habitat connectivity, early life history diversity, and survival benefits.

Diefenderfer, Heida L.; Johnson, Gary E.; Sather, Nichole K.; Skalski, J. R.; Dawley, Earl M.; Coleman, Andre M.; Ostrand, Kenneth G.; Hanson, Kyle C.; Woodruff, Dana L.; Donley, Erin E.; Ke, Yinghai; Buenau, Kate E.; Bryson, Amanda J.; Townsend, Richard L.

2011-10-01

168

An Ecosystem-Based Restoration Plan with Emphasis on Salmonid Habitats in the Lower Columbia River and Estuary  

SciTech Connect

The Bonneville Power Administration (BPA), in coordination with the U. S. Army Corps of Engineers (COE) and NOAA Fisheries, originated this project (BPA Project No. 2002-076; Contract No. DE-AC06-76RL01830, Release No. 652-24). Their intent was to develop a useful habitat restoration plan for the lower Columbia River and estuary to help guide restoration efforts and fulfill Reasonable and Prudent Alternative Action 159 of the 2000 National Marine Fisheries Service Biological Opinion on operation of the Federal Columbia River Power System. This document focuses on salmon habitat, although its ecosystem-based approach necessarily affects other species as well. Salmon habitat restoration is best undertaken within the context of other biota and physical processes using an ecosystem perspective. The anticipated audience for the plan includes entities responsible for, interested in, or affected by habitat restoration in the lower Columbia River and estuary. Timeframes to apply this plan extend from the immediate (2003-2004) to the near-term (2005-2006) to the long-term (2007 and beyond). We anticipate and encourage that the plan be revised as new knowledge and experience are attained. A team comprised of the Columbia River Estuary Study Taskforce (CREST), the Lower Columbia River Estuary Partnership (Estuary Partnership), and Pacific Northwest National Laboratory (PNNL) wrote this document. The BPA and the COE, as the responsible Action Agencies, provided technical oversight. The Estuary Partnership's Science Work Group, NOAA Fisheries Habitat Conservation Division, Northwest Power Planning Council (NPPC) staff, and state and tribal fisheries management agencies reviewed drafts. The Independent Scientific Advisory Board of the NPPC reviewed and commented on the 90% draft. Revisions were incorporated into the final draft document subsequently released for public review. Extensive efforts were made to ensure a sound technical and policy basis and to solicit input from all interested parties.

Johnson, Gary E.; Thom, Ronald M.; Whiting, Allan H.; Sutherland, George B.; Berquam, Taunja J.; Ebberts, Blaine; Ricci, Nicole M.; Southard, John A.; Wilcox, Jessica D.

2003-10-14

169

Geographic signatures of North American West Coast estuaries  

Microsoft Academic Search

West Coast estuaries are geologically young and composed of a variety of geomorphological types. These estuaries range from\\u000a large fjords to shallow lagoons; from large to low freshwater flows. Natural hazards include E1 Niños, strong Pacific storms,\\u000a and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable\\u000a shellfish, waterfowl and marine birds,

Robert Emmett; ROBERTO LLANSO ´; Jan Newton; Ron Thom; Michelle Hornberger; Cheryl Morgan; Colin Levings; Andrea Copping; Paul Fishman

2000-01-01

170

A statistical–dynamical method for predicting estuary morphology  

Microsoft Academic Search

A statistical–dynamical model for estuary morphodynamics is presented and demonstrated with a case study on the Humber Estuary,\\u000a UK. The model presented here is hybrid in nature where simplified process dynamics are combined with a data-driven approach.\\u000a The modelling methodology uses an inverse technique to construct an unknown source function in the model-governing equation,\\u000a using historic measurements of estuary bathymetry.

Dominic E. Reeve; Harshinie Karunarathna

2011-01-01

171

Degree of Fragmentation Affects Fish Assemblage Structure in Andros Island (Bahamas) Estuaries  

E-print Network

Degree of Fragmentation Affects Fish Assemblage Structure in Andros Island (Bahamas) Estuaries with different degrees of fragmentation on Andros Island, Bahamas. Estuaries were classified a priori into four

Langerhans, Brian

172

Impact of climate change on Gironde Estuary  

NASA Astrophysics Data System (ADS)

Within the THESEUS European project, a simplified mathematical model for storm surge levels in the Bay of Biscay was adjusted on 10 events at Le Verdon using wind and pressure fields from CLM/SGA, so that the water levels at Le Verdon have the same statistic quantiles as observed tide records for the period [1960-2000]. The analysis of future storm surge levels shows a decrease in their quantiles at Le Verdon, whereas there is an increase of the quantiles of total water levels. This increase is smaller than the sea level rise and gets even smaller as one enters farther upstream in the estuary. A numerical model of the Gironde Estuary was then used to evaluate future water levels at 6 locations of the estuary from Le Verdon to Bordeaux and to assess the changes in the quantiles of water levels during the XXIst century using ONERC's pessimistic scenario for sea level rise (60 cm). The model was fed by several data sources : wind fields at Royan and Mérignac interpolated from the grid of the European Climatolologic Model CLM/SGA, a tide signal at Le Verdon, the discharges of Garonne (at La Réole), the Dordogne (at Pessac) and Isle (at Libourne). A series of flood maps for different return periods between 2 and 100 years and for four time periods ([1960-1999], [2010-2039], [2040-2069] and [2070-2099]) have been built for the region of Bordeaux. Quantiles of water levels in the floodplain have also been calculated. The impact of climate change on the evolution of flooded areas in the Gironde Estuary and on quantiles of water levels in the floodplain mainly depends on the sea level rise. Areas which are not currently flooded for low return periods will be inundated in 2100. The influence of river discharges and dike breaching should also be taken into account for more accurate results.

Laborie, Vanessya; Hissel, François; Sergent, Philippe

2014-05-01

173

Migratory Behavior and Survival of Juvenile Salmonids in the Lower Columbia River and Estuary in 2009  

SciTech Connect

The study reported herein was funded as part of the Anadromous Fish Evaluation Program, which is managed by the U.S. Army Corps of Engineers (USACE). The Anadromous Fish Evaluation Program study code is EST P 02 01: A Study of Salmonid Survival and Behavior through the Columbia River Estuary Using Acoustic Tags. The study was conducted by the Pacific Northwest National Laboratory (PNNL) and National Oceanic and Atmospheric Administration (NOAA) Fisheries for the USACE Portland District. Estimated survival of acoustic-tagged juvenile Chinook salmon and steelhead through the lower Columbia River and estuary in 2009 was lowest in the final 50 km of the estuary. Probability of survival was relatively high (>0.90) for yearling and subyearling Chinook salmon from the Bonneville Dam forebay (rkm 236) to Three-tree Point (rkm 49.6). Survival of juvenile Chinook salmon declined sharply through the lower 50 km of the estuary. Acoustic-tagged steelhead smolts did not survive as well as juvenile Chinook salmon between Bonneville Dam and the mouth of the Columbia River. Steelhead survival began to decline farther upstream (at rkm 86) relative to that of the Chinook salmon stocks. Subyearling Chinook salmon survival decreased markedly as the season progressed. It remains to be determined whether later migrating subyearling Chinook salmon are suffering increasing mortality as the season progresses or whether some portion of the apparent loss is due to fish extending their freshwater residence. This study provided the first glimpse into what promises to be a very informative way to learn more about how juvenile salmonid passage experiences through the FCRPS may influence their subsequent survival after passing Bonneville Dam. New information regarding the influence of migration pathway through the lower 50 km of the Columbia River estuary on probability of survival of juvenile salmonids, combined with increased understanding regarding the foraging distances and time periods of avian predators should prove useful in developing or assessing management actions to reduce losses of juvenile salmonid smolts that attempt to pass through the estuary on their seaward migration.

McMichael, Geoffrey A.; Harnish, Ryan A.; Bellgraph, Brian J.; Carter, Jessica A.; Ham, Kenneth D.; Titzler, P. Scott; Hughes, Michael S.

2010-08-01

174

An Ecosystem-Based Restoration Plan with Emphasis on Salmonid Habitats in the Lower Columbia River and Estuary  

Microsoft Academic Search

The Bonneville Power Administration (BPA), in coordination with the U. S. Army Corps of Engineers (COE) and NOAA Fisheries, originated this project (BPA Project No. 2002-076; Contract No. DE-AC06-76RL01830, Release No. 652-24). Their intent was to develop a useful habitat restoration plan for the lower Columbia River and estuary to help guide restoration efforts and fulfill Reasonable and Prudent Alternative

Gary E. Johnson; Ronald M. Thom; Allan H. Whiting; George B. Sutherland; Taunja J. Berquam; Blaine Ebberts; Nicole M. Ricci; John A. Southard; Jessica D. Wilcox

2003-01-01

175

Tide-driven fluid mud transport in the Ems estuary  

NASA Astrophysics Data System (ADS)

The Ems estuary, located at the border between The Netherlands and Germany, experienced a significant change of the hydrodynamic regime during the past decades, as a result of extensive river engineering. With the net sediment transport now being flood-oriented, suspended sediment concentrations have increased dramatically, inducing siltation and formation of fluid mud layers, which, in turn, influence hydraulic flow properties, such as turbulence and the apparent bed roughness. Here, the process-based understanding of fluid mud is essential to model and predict mud accumulation, not only regarding the anthropogenic impact, but also in view of the expected changes of environmental boundary conditions, i.e., sea level rise. In the recent past, substantial progress has been made concerning the understanding of estuarine circulation and influence of tidal asymmetry on upstream sediment accumulation. While associated sediment transport formulations have been implemented in the framework of numerical modelling systems, in-situ data of fluid mud are scarce. This study presents results on tide-driven fluid mud dynamics, measured during four tidal cycles aside the navigation channel in the Ems estuary. Lutoclines, i.e., strong vertical density gradients, were detected by sediment echo sounder (SES). Acoustic Doppler current profiles (ADCP) of different acoustic frequencies were used to determine hydrodynamic parameters and the vertical distribution of suspended sediment concentrations in the upper part of the water column. These continuous profiling measurements were complemented by CTD, ADV, and OBS casts. SES and ADCP profiles show cycles of fluid mud entrainment during accelerating flow, and subsequent settling, and the reformation of a lutocline during decelerating flow and slack water. Significant differences are revealed between flood and ebb phase. Highest entrainment rates are measured at the beginning of the flood phase, associated with strong current shear and rapid vertical mixing, inducing the highest instantaneous suspended sediment flux measured during the tidal cycle. During decelerating flood currents a lutocline is again established at a certain distance above the consolidated river bed. During slack water after the flood phase the concentration gradient increases and the thickness of the fluid mud layer below is constant, also during a significant part of the ebb phase. As water depth decreases during ebb, entrainment occurs only at the upper part of the fluid mud layer. The suspended sediment flux is low compared to the flood phase. These observations are further elaborated using turbulence parameters obtained from ADV and ADCP, explaining the difference between ebb and flood concerning the vertical location of the maximum concentration gradient. This study is funded through DFG-Research Center / Excellence Cluster "The Ocean in the Earth System". The Senckenberg Institute and the Federal Waterways Engineering and Research Institute are acknowledged for technical support.

Becker, Marius; Maushake, Christian; Winter, Christian

2014-05-01

176

Modeling long-term morphological change and mixed bed sediment evolution in the Deschutes Estuary  

NASA Astrophysics Data System (ADS)

For modeling systems in extreme disequilibrium, such as an impounded estuary or diked coastal wetland, coupling between the bed and the hydrodynamic forces from tides and rivers that can redistribute accumulated sediment is vital. The feedback among the evolving bed sediment grain size, bathymetry, sediment transport, and hydrodynamics increases in importance when the time scale extends beyond months to years or decades. The Deschutes Estuary Feasibility Study, in Olympia, Washington, which is investigating estuarine response to removing a dam, provides an opportunity to examine this coupling. A hydrodynamic and sediment transport model was constructed with the numerical model Delft3D to predict the flow, sediment transport, and morphological change under several estuary restoration scenarios. Multi-year (1, 3 and 10 year) morphological simulations required simplifying data inputs and implementing a time-scale acceleration technique. A sediment discharge climatology based on the Deschutes River hydrograph and a representative tide selected from the spring-neap tidal cycle are used to force the model. To reduce computational time, a variable morphological factor is employed, which relates the hydrodynamic and the morphologic time scales. Surface grab samples were collected to quantify the dominant bed sediment grain sizes but no other information regarding sediment erodibility was available. Four sediment sizes are used to represent the bed: clay (2 ?m), silt (31 ?m), sand (200 ?m) and gravel (2000 ?m). Sediment properties, such as critical shear stress for erosion, erosion rate, and dry density of mud fractions, are based on published observations in similar environments, and sensitivity to a range of values is tested. Long-term morphological simulations after removing the dam show that as the primary channel erodes, the sediment in the channel coarsens and sediment along the adjacent tide flats gets finer. A portion of the fine sediment that erodes from the estuary also accumulates outside of the estuary. The volume of sediment transported in the model varies by an order of magnitude between the lowest and highest erodibility values. The amount of erosion and degree of grain-size evolution through subsequent years depends greatly on the erodibility parameters. Direct field measurements of the sediment erodibility would assist in calibrating the model and reducing uncertainty. Regardless of the erodibility values, the evolving bed plays a primary role in determining the flow patterns and velocities, both of which affect the rate of morphological change.

George, D. A.; Gelfenbaum, G.; Lesser, G. R.; Stevens, A. W.

2006-12-01

177

The Hydrography of the Chupa Estuary, White Sea, Russia  

Microsoft Academic Search

This study was undertaken to determine the fate and fluxes of materials from Arctic estuaries to the coastal zone. The paper is the first of a series addressing questions relating to the physics and chemistry of the region. Three seasonal cruises were undertaken in the Chupa Estuary, White Sea, Russia; in summer (July 1994), autumn (September, 1995) and spring (May\\/June

R. J. M. Howland; A. N. Pantiulin; G. E. Millward; R. Prego

1999-01-01

178

Fate of methane in the Hudson River and estuary  

Microsoft Academic Search

Methane (CH4) concentrations and oxidation rates were measured throughout the Hudson River Estuary in March and August of 1991. Methane concentrations ranged from 50 to 940 nM and were supersaturated with respect to the atmosphere along the entire length of the river, with generally higher CH4 values in the lower, saline portion of the estuary. A seasonally averaged diffusive flux

Marie A. de Angelis; Mary I. Scranton

1993-01-01

179

Behavior of metals in the Amur River estuary  

Microsoft Academic Search

Biogeochemical processes in estuaries determine to a significant extent the further life of chemical compounds, including metals transported by rivers. Therefore, the characteristics of the behavior of metals in waters with intermediate salinity at the river?sea interface have both scientific and practical significance [1?5]. In terms of estimation of the concentrations of dissolved metals, the estuary of the Amur River,

V. M. Shul’kin

2006-01-01

180

LOWER COLUMBIA RIVER ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN  

EPA Science Inventory

An estuary is the area where the fresh water of a river meets the salt water of an ocean. In the Columbia River system, this occurs in the lower 46 river miles. In an estuary, the river has a direct, natural connection with the open sea. This transition from fresh to salt water c...

181

Real time simulation of nitrogen cycle in an estuary  

Microsoft Academic Search

A water quality model containing seven nitrogen storage variables appropriate to an aerobic, nitrogen limited, aquatic ecosystem is described. An idealized estuary is used to demonstrate coupling between hydrodynamic transport, mixing, and biochemical transformations. Nutrient concentrations are highly sensitive to the representation of real time (intratidal cycle) transport. Application of the model to the Potomac estuary illustrates the large temporal

T. O. Najarian; D. R. F. Harleman

1977-01-01

182

Flood and ebb dominance in estuaries in Korea  

Microsoft Academic Search

Ebb dominance, which is mainly observed at the Youngsan River estuary (YRE) and flood dominance at the Keum River estuary (KRE) are conspicuous features in the southwestern coastal zones of Korea. In considering the sources of this asymmetry, which include, not only bottom friction, irregular bathymetry and tidal flats, other issues also need to be considered, since dominance occurs extensively

J. W Kang; K. S Jun

2003-01-01

183

Primary Productivity Regime and Nutrient Removal in the Danube Estuary  

Microsoft Academic Search

The primary productivity regime, as well as the distribution of dissolved inorganic nutrients and particulate organic matter in the Danube estuary, were investigated during several cruises at different discharge regimes of the Danube River. The shallowness of the upper surface layer due to insignificant tidal mixing and strong stratification of the Danube estuary, as well as the high nutrient concentrations,

C. Humborg

1997-01-01

184

ASSESSING THE ECOLOGICAL CONDITION OF SOUTHEAST U. S. ESTUARIES  

EPA Science Inventory

As a means to assess ecological condition, 151 stations located in southeastern estuaries from Cape Henry, Virginia to Biscayne Bay, Florida were sampled by state agencies during the summer of 2000 using a probabilistic design. The design used 8 size classes of estuaries ranging ...

185

YAQUINA BAY AND BEYOND: WHAT SHAPE ARE OUR ESTUARIES IN?  

EPA Science Inventory

The great natural beauty of Oregon's estuaries gives an impression of systems that are far less altered than those in other areas of the US. However, over the years, Yaquina Bay and other western estuaries have been variously affected by habitat loss and alteration, over harvest...

186

LIMNETIC LARVAL FISH OF THE MAUMEE AND SANDUSKY RIVER ESTUARIES  

EPA Science Inventory

A total of 17 taxa were collected in the Maumee River estuary during sampling periods in 1975, 1976, and 1977. A total of 11 taxa were collected from the Sandusky River estuary in 1976. Gizzard shad/alewife, Dorosoma cepedianum/Alosa pseudoharengus, white bass/white perch, Morone...

187

Three dimensional water quality modeling of a shallow subtropical estuary.  

PubMed

Knowledge of estuarine hydrodynamics and water quality comes mostly from studies of large estuarine systems. The processes affecting algae, nutrients, and dissolved oxygen (DO) in small and shallow subtropical estuaries are relatively less studied. This paper documents the development, calibration, and verification of a three dimensional (3D) water quality model for the St. Lucie Estuary (SLE), a small and shallow estuary located on the east coast of south Florida. The water quality model is calibrated and verified using two years of measured data. Statistical analyses indicate that the model is capable of reproducing key water quality characteristics of the estuary within an acceptable range of accuracy. The calibrated model is further applied to study hydrodynamic and eutrophication processes in the estuary. Modeling results reveal that high algae concentrations in the estuary are likely caused by excessive nutrient and algae supplies in freshwater inflows. While algal blooms may lead to reduced DO concentrations near the bottom of the waterbody, this study indicates that stratification and circulation induced by freshwater inflows may also contribute significantly to bottom water hypoxia in the estuary. It is also found that high freshwater inflows from one of the tributaries can change the circulation pattern and nutrient loading, thereby impacting water quality conditions of the entire estuary. Restoration plans for the SLE ecosystem need to consider both a reduction of nutrient loading and regulation of the freshwater discharge pattern. PMID:23122270

Wan, Yongshan; Ji, Zhen-Gang; Shen, Jian; Hu, Guangdou; Sun, Detong

2012-12-01

188

Controlling Invasive Cordgrasst A Tale of Two Estuaries  

Microsoft Academic Search

Open intertidal mud is a hallmark of Pacific estuaries. Shore birds, marine life, and the traditional fishing and oystering in these habitats depend upon openness. Alien cordgrasses of the genus Spartina threaten these estuaries. Growing further down the intertidal gradient than any other land plant, Spartina alterniflora (Smooth Cordgrass, introduced from the Atlantic coast) and Spartina anglica (English Cordgrass, introduced

Donald R. Strong; Debra R. Ayres

189

Design your Engineering  

E-print Network

universities in the world. Its eminent reputation is founded on an out- standing faculty and equally brilliant's Mining Engineering Program is the oldest in Canada and has traditionally had the highest reputation: =Consulting =Corporate management =Engineering design and technology =Environmental engineering =Feasibility

Barthelat, Francois

190

Municipal District Heating and Cooling Co-generation System Feasibility Research  

E-print Network

ICEBO2006, Shenzhen, China Building Commissioning for Energy Efficiency and Comfort, Vol.VI-7-4 Municipal District Heating and Cooling Co-generation System Feasibility Research Wencheng Zhang Wenji Guan Yungang Pan Gao Ding... Xiaochun Song Senior Engineer Senior Engineer Senior Engineer Senior Engineer Senior Engineer China Architecture design & research Group Beijing, China mep-h@263.net Yali Zhang Ying Li Hang Wei Yuping He Engineer Engineer Engineer Senior...

Zhang, W.; Guan, W.; Pan, Y.; Ding, G.; Song, X.; Zhang, Y.; Li, Y.; Wei, H.; He, Y.

2006-01-01

191

The Oncor Geodatabase for the Columbia Estuary Ecosystem Restoration Program: Annual Report, 2012  

SciTech Connect

Pacific Northwest National Laboratory (PNNL) conducted this project for the U.S. Army Corps of Engineers, Portland District (Corps). The purpose of the project is to develop a geospatial, web-accessible database (called “Oncor”) for action effectiveness and related data from monitoring and research efforts for the Columbia Estuary Ecosystem Restoration Program (CEERP). The intent is for the Oncor database to enable synthesis and evaluation, the results of which can then be applied in subsequent CEERP decision-making. This is the first annual report in what is expected to be a 3- to 4-year project, which commenced on February 14, 2012.

Coleman, Andre M.; Johnson, Gary E.; Borde, Amy B.; Diefenderfer, Heida L.; Sather, Nichole K.; Seiple, Timothy E.; Serkowski, John A.

2013-11-10

192

PECONIC ESTUARY: RECREATIONAL AND RESOURCE ECONOMIC VALUES FOR THE PECONIC ESTUARY SYSTEM  

EPA Science Inventory

The environmental and natural resources ("natural assets") of the Peconic Estuary System--the bay waters, beaches, wetlands, ecosystems, habitats, and parks and watershed lands--provide many services to the public. Outdoor recreation, scenic views, and the productivity of wetland...

193

Approaches for Development of Nutrient Criteria in Oregon Estuaries With a Focus on Tillamook Estuary  

EPA Science Inventory

Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

194

A hybrid approach to estimate chromophoric dissolved organic matter in turbid estuaries from  

E-print Network

A hybrid approach to estimate chromophoric dissolved organic matter in turbid estuaries from to derive CDOM absorption coefficient at 443 nm (ag(443), m-1 ) in a turbid estuary (Tampa Bay) from MODIS discharge. Testing of the approach over another turbid estuary (Chesapeake Bay, the largest estuary in the U

Meyers, Steven D.

195

Salmon Life Histories, Habitats, and Food Webs in the Columbia River Estuary  

E-print Network

Salmon Life Histories, Habitats, and Food Webs in the Columbia River Estuary Daniel J. Bottom NOAA management efforts in the Columbia River estuary on behalf of salmon: (1) the estuary is irrelevant stocks throughout the Columbia River Basin. The Columbia River estuary contributes to salmon life history

196

AN APPROACH TO DEVELOPING NUTRIENT CRITERIA FOR PACIFIC NORTHWEST ESTUARIES: A CASE STUDY OF YAQUINA ESTUARY, OREGON  

EPA Science Inventory

NHEERL scientists have developed an approach that could be used by the State of Oregon for development of nutrient and other water quality criteria for the Yaquina Estuary, Oregon. The principle objective in setting protective criteria is to prevent future degradation of estuari...

197

Mercury sources and transformations in a man-perturbed tidal estuary: The Sinnamary Estuary, French Guiana  

NASA Astrophysics Data System (ADS)

The distribution, partition and speciation of mercury (Hg) were studied along the redox gradient of an anthropogenically perturbed tropical estuary, the Sinnamary Estuary in French Guiana. This system is a partially mixed estuary characterized by an anoxic freshwater end-member, while the marine end-member consists of the Amazon Plume. The set up of an artificial oxygenation system in the anoxic freshwater end-member generates sharp gradients of major chemical species (iron, sulfides, etc.) coupled with intense organic matter (OM) turnover. The coexistence of oxygenated waters and dissolved sulfides in an organic rich environment depicts the Upper Sinnamary Estuary (USE: part of Sinnamary Estuary under the tidal influence but upstream of the salt intrusion) as a potential site for Hg methylation. The concentrations of all mercury compounds (HgT) in the unfiltered samples (HgT UNF), in the dissolved (HgT D) and particulate (HgT P) phases of the USE average 11 ± 3, 6 ± 2 and 5 ± 3 (i.e. 600 ± 200 pmol g -1) pmol L -1, respectively. Average concentrations of monomethylmercury (MMHg) in the unfiltered (MMHg UNF), dissolved (MMHg D) and particulate (MMHg P) phases were 3.7 ± 1.0, 2.0 ± 0.9 and 1.8 ± 1.2 (i.e. 220 ± 130 pmol g -1) pmol L -1, respectively. Water oxygenation and sulfides concentrations emerged to play a critical role in controlling MMHg levels. Additionally, iron cycling, acid-base mechanisms, and redox-dependent processes were involved in the MMHg partitioning between phases. Overall, the USE constitutes a biogeochemical reactor that gathers partitioning and methylation processes. The permanent MMHg inputs from the anoxic freshwater end-member combined with the intense endogenous Hg methylation ensures high-MMHg levels in both dissolved and particulate phases. To illustrate, the USE exports 60 ± 20% more MMHg UNF than it imports: 5.5 ± 0.7 vs. 3.5 ± 1.2 kg year -1.

Muresan, B.; Cossa, D.; Coquery, M.; Richard, S.

2008-11-01

198

MAIA Estuaries 1997-98 Data  

NSDL National Science Digital Library

The Mid Atlantic Integrated Assessment program (MAIA) of the Environmental Protection Agency (EPA) has released these estuaries data for 1997-98. Data and Metadata may be viewed or downloaded (text or .pdf) for the following variables: Sampling Station Location Data, Station Visit Data, Water Quality Physical Measurements, Water Quality- Nutrients Data, Sediment Grain Size Data, Sediment Toxicity Data, Sediment Chemistry Data, Benthic Community Grain Size Data, Benthic Abundance Data, Benthic Biomass Data, Benthic Community Summary Data, Chemical Analyte Code Table, and Benthic Taxon Code Table.

199

Change in Land Cover along the Lower Columbia River Estuary as Determined from Landsat Thematic Mapper (TM) Imagery, Technical Report 2003.  

SciTech Connect

The Lower Columbia River Estuary Management Plan (Jerrick, 1991) recognizes the positive relationship between the conservation of fish and wildlife habitat, and sustaining their populations. An important component of fish and wildlife conservation and management is the identification of habitats, trends in habitat change, and delineation of habitat for preservation, restoration or enhancement. Alterations to the environment, such as hydropower generation, dredging, forestry, agriculture, channel alteration, diking, bank stabilization and floodplain development, have dramatically altered both the type and distribution of habitats along the Columbia River Estuary (CRE) and its floodplain. Along the Columbia River, tidally influenced habitats occur from the river mouth to the Bonneville Dam, a distance of 230 km. If we are to effectively manage the natural resources of the Columbia River ecosystem, there is a need to understand how habitats have changed because fish and wildlife populations are known to respond to changes in habitat quality and distribution. The goal of this study was to measure the amount and type of change of CRE land cover from 1992 to 2000. We performed a change analysis on two spatial data sets describing land cover along the lower portion of the estuary (Fig. 1). The 1992 data set was created by the NOAA Coastal Remote Sensing, Coastal Change Analysis Program (C-CAP) in cooperation with Columbia River Estuary Study Task Force (CREST), the National Marine Fisheries Service (NMFS) Point Adams Field Station, and State of Washington Department of Natural Resources (DNR). The 2000 data set was produced by Earth Design Consultants, Inc. (EDC) and the Wetland Ecosystem Team (WET: University of Washington) as part of a larger Lower Columbia River Estuary Partnership (Estuary Partnership) habitat mapping study. Although the image classification methodologies used to create the data sets differed, both data sets were produced by classifying Landsat Thematic Mapper (TM) satellite imagery, making it feasible to assess land cover changes between 1992 and 2000.

Garono, Ralph; Anderson, Becci; Robinson, Rob

2003-10-01

200

14-plex Feasibility Report  

SciTech Connect

The Native Village of Unalakleet project was a feasibility study for a retrofit of a “tribally owned” three story, 14 apartment complex located in Unalakleet, Alaska. The program objective and overall goal was to create a plan for retrofitting to include current appraised value and comparable costs of new construction to determine genuine feasibility as low-income multi-family housing for tribal members.

Kotongan, Victoria Hazel [Native Village of Unalakleet

2013-06-21

201

[Vulnerability assessment on the coastal wetlands in the Yangtze Estuary under sea-level rise].  

PubMed

To study the response of coastal wetlands to climate change, assess the impacts of climate change on the coastal wetlands and formulate feasible and practical mitigation strategies are the important prerequisite for securing coastal ecosystems. In this paper, the possible impacts of sea level rise caused by climate change on the coastal wetlands in the Yangtze Estuary were analyzed by the Source-Pathway-Receptor-Consequence (SPRC) model and IPCC definition on the vulnerability. An indicator system for vulnerability assessment was established, in which sea-level rise rate, subsidence rate, habitat elevation, inundation threshold of habitat and sedimentation rate were selected as the key indicators. A quantitatively spatial assessment method based on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability index for the assessment of coastal wetlands in the Yangtze Estuary under the scenarios of sea-level rise. The vulnerability assessments on the coastal wetlands in the Yangtze Estuary in 2030 and 2050 were performed under two sea-level rise scenarios (the present sea-level rise trend over recent 30 years and IPCC A1F1 scenario). The results showed that with the projection in 2030 under the present trend of sea-level rise (0.26 cm x a(-1)), 6.6% and 0.1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9.8% and 0.2% of the coastal wetlands were in low and moderate vulnerabilities, respectively. With the projection in 2030 under the A1F1 scenario (0.59 cm x a(-1)), 9.0% and 0.1% of the coastal wetlands were in the low and moderate vulnerabilities, respectively; and in 2050, 9.5%, 1.0% and 0.3% of the coastal wetlands were in the low, moderate and high vulnerabilities, respectively. PMID:24830257

Cui, Li-Fang; Wang, Ning; Ge, Zhen-Ming; Zhang, Li-Quan

2014-02-01

202

What is the future fate of estuaries given nutrient over-enrichment, freshwater diversion and low flows?  

Microsoft Academic Search

Freshwater inflow is central to the definition of estuaries and if we lose control of the quantity of freshwater flow or discharge (including seasonal timing) to estuaries, then freshwater water quality has the potential to become a moot issue in estuarine ecosystems (Definition of estuaries: estuaries (aestus=tide) are physico-chemically, geomorphically, and biotically diverse ecosystems. Although numerous definitions of estuaries exist,

David A. Flemer; Michael A. Champ

2006-01-01

203

Sediment Transport Processes In River Dominated Sub-Tropical Estuaries  

NASA Astrophysics Data System (ADS)

The objective of this study is to present a comparative assessment of the largest three river dominated estuaries in the southern coast of the state of Santa Catarina, Brazil (Tubarão, Araranguá and Mampituba estuaries). The study was focused on mechanisms of transport of suspended sediments influenced by its morphologic and hydrodynamics characteristics. As shown in D'Aquino et al (2011), these estuaries share common attributes (climate and tides) and follow the basic conceptual model of fine sediment transport (presented by Toldo & Schettini (2006). However, each one has its own particularities regarding the geographical setting, land use, hypsometry, outfall, etc. The methodology used to the field measurements was the same for all estuaries, aiming at measuring the currents, water level, salinity, temperature and turbidity near the outfall for at least two complete tidal cycles (~25 hours). All the campaigns were carried on under syzygya tide conditions. During the sample collecting period, a longitudinal profile was conducted in each estuary, through acquisitions of salinity and temperature of the water column in every kilometer. In the Tubarão and Araranguá rivers estuaries, the concentration of suspended particulate matter (SPM) is mostly influenced by the periods of incoming tide, flood currents. In the Mampituba river estuary, the flocculation process was observed during the encounter of fresh and salt water in every tide entrance. It was possible to observe that the Araranguá river estuary, in what concerns the bottom SPM, responds to the variation of salinity and currents along the bottom. The Tubarão estuary presents a relation between the salinity and the bottom currents. In the Mampituba estuary no relevant correlation was found between the SPM, the salinity, and the bottom currents. Those aspects demonstrate that even sharing some characteristics there are significant differences among these estuaries. In addition, as a result of the comparative study, an analytical model was proposed that correlates the fluvial discharge, salt wedge, and SPM. This model might represent a tool to encourage discussions and help the scientific exploration of the estuaries in the south of Santa Catarina.

DAquino, Carla; Schettini, Carlos

2014-05-01

204

The Deschutes Estuary Restoration Feasibility Study: development of a process-based morphological model  

E-print Network

transport after dam removal will also be modeled. Key components of the model include tidal currents. Several restoration solutions have been proposed, including removal of the dam and widening the opening Continual sediment accumulation in Capitol Lake since the damming of the Deschutes River in 1951 has altered

205

Seasonal Patterns in the Fish and Crustacean Community of a Turbid Temperate Estuary (Zeeschelde Estuary, Belgium)  

NASA Astrophysics Data System (ADS)

Fish and crustaceans were sampled for 1 year in the upper reaches of a temperate estuary characterized by high turbidity and a tidal range of up to 5 m. Samples were taken in the cooling-water circuit of the Doel Nuclear Power station (Zeeschelde, Belgium). Between July 1994 and June 1995, 55 fish species, two shrimp species and four crab species were recorded. The fish community was composed of 36 marine species, 16 freshwater species and three diadromous species. Shrimps, Gobiidae and Clupeidae dominated the samples both in numbers and biomass. An exceptionally clear seasonal succession was observed in the species composition. It is argued that young fish and crustaceans use the highly turbid Zeeschelde Estuary as a refuge from predators.

Maes, J.; Taillieu, A.; Van Damme, P. A.; Cottenie, K.; Ollevier, F.

1998-08-01

206

Multi-Scale Action Effectiveness Research in the Lower Columbia River and Estuary, 2011 - FINAL ANNUAL REPORT  

SciTech Connect

The study reported here was conducted by researchers at Pacific Northwest National Laboratory (PNNL), the Oregon Department of Fish and Wildlife (ODFW), the University of Washington (UW), and the National Marine Fisheries Service (NMFS) for the U.S. Army Corps of Engineers, Portland District (USACE). This research project was initiated in 2007 by the Bonneville Power Administration to investigate critical uncertainties regarding juvenile salmon ecology in shallow tidal freshwater habitats of the lower Columbia River. However, as part of the Washington Memorandum of Agreement, the project was transferred to the USACE in 2010. In transferring from BPA to the USACE, the focus of the tidal freshwater research project shifted from fundamental ecology toward the effectiveness of restoration in the Lower Columbia River and estuary (LCRE). The research is conducted within the Action Agencies Columbia Estuary Ecosystem Restoration Program (CEERP). Data reported herein spans the time period May 2010 to September 2011.

Sather, Nichole K.; Storch, Adam; Johnson, Gary E.; Teel, D. J.; Skalski, J. R.; Bryson, Amanda J.; Kaufmann, Ronald M.; Woodruff, Dana L.; Blaine, Jennifer; Kuligowski, D. R.; Kropp, Roy K.; Dawley, Earl M.

2012-05-31

207

Mixing processes and hydraulic control in a highly stratified estuary  

E-print Network

This thesis utilizes field data from the Fraser River Estuary, a highly stratified system located in southwestern British Columbia, Canada, to investigate the nature of mixing processes in a highly stratified environment, ...

MacDonald, Daniel George, 1970-

2003-01-01

208

MAPPING BURROWING SHRIMP AND SEAGRASS IN YAQUINA ESTUARY  

EPA Science Inventory

Burrowing shrimp and seagrasses create extensive intertidal and shallow subtidal habitats within Pacific NW estuaries. Maps of their populations are useful to inform estuarine managers of locations that deserve special consideration for conservation, and to inform oyster farmers...

209

oceanservice.noaa.gov/education 1 ESTUARY SUBJECT REVIEW  

E-print Network

-shaped deposits of sediment at the mouth of a river. 27. __________ estuaries are formed when the earth's tectonic plates run into or fold-up underneath each other. 28. __________ are steep-walled river valleys created

210

Biogeochemistry of the Kem' River estuary, White Sea (Russia)  

Microsoft Academic Search

The biogeochemistry of the river-sea interface was studied in the Kem' River (the largest river flowing to the White Sea from Karelian coast) estuary and adjacent area of the White Sea onboard the RV \\

V. R. Shevchenko; Y. S. Dolotov; N. N. Filatov; T. N. Alexeeva; A. S. Filippov; E.-M. Nöthig; A. N. Novigatsky; L. A. Pautova; A. V. Platonov; N. V. Politova; T. N. Rat'kova; R. Stein

2005-01-01

211

SAN JUAN BAY ESTUARY PROGRAM IMPLEMENTATION REVIEW ATTACHMENTS  

EPA Science Inventory

A compilation of attachments referenced in the San Juan Bay Estuary Program Implementation Review (2004). Materials include, entity reports, water and sediment quality action plans, progress reports, correspondence with local municipalities and Puerto Rican governmental agencies,...

212

MODIS water quality algorithms for northwest Florida estuaries  

EPA Science Inventory

Synoptic and frequent monitoring of water quality parameters from satellite is useful for determining the health of aquatic ecosystems and development of effective management strategies. Northwest Florida estuaries are classified as optically-complex, or waters influenced by chlo...

213

A PROBABILISTIC SURVEY OF SEDIMENT TOXICITY IN WEST COAST ESTUARIES  

EPA Science Inventory

A probabalistic survey of coastal condition assessment was conducted in 1999 by participants in US EPA's Environmental Monitoring and Assessment Program (EMAP). The survey targeted estuaries along the outer coasts of Washington, Oregon and California, including the lower Columbi...

214

Evaluating Causes of Ecological Impairments in the Estuaries of Ukraine  

EPA Science Inventory

Ukrainian estuaries have not undergone a systematic evaluation of the causes of ecological impairments caused by anthropogenic contamination. The objective of this evaluation is to use recently developed diagnostic tools to determine the causes of benthic ecological impairments. ...

215

FOOD PATHWAYS ASSOCIATED WITH PENAEID SHRIMPS IN A MANGROVEFRINGED ESTUARY  

E-print Network

FOOD PATHWAYS ASSOCIATED WITH PENAEID SHRIMPS IN A MANGROVE·FRINGED ESTUARY ALLAN W. STONERl AND Ro, particularly where wetland habitats such as marsh grasses or mangroves are prominent coastal fea- tures

216

Assessing the Impact of Human Activities on British Columbia's Estuaries  

PubMed Central

The world’s marine and coastal ecosystems are under threat and single-sector management efforts have failed to address those threats. Scientific consensus suggests that management should evolve to focus on ecosystems and their human, ecological, and physical components. Estuaries are recognized globally as one of the world’s most productive and most threatened ecosystems and many estuarine areas in British Columbia (BC) have been lost or degraded. To help prioritize activities and areas for regional management efforts, spatial information on human activities that adversely affect BC’s estuaries was compiled. Using statistical analyses, estuaries were assigned to groups facing related threats that could benefit from similar management. The results show that estuaries in the most populated marine ecosections have the highest biological importance but also the highest impacts and the lowest levels of protection. This research is timely, as it will inform ongoing marine planning, land acquisition, and stewardship efforts in BC. PMID:24937486

Robb, Carolyn K.

2014-01-01

217

LOUISIANIAN PROVINCE DEMONSTRATION REPORT - EMAP-ESTUARIES: 1991  

EPA Science Inventory

This report summarizes the Louisianian Demonstration Project conducted by the Estuaries Resource Group of the Environmental Monitoring and Assessment Program (EMAP), a national program initiated by EPA to integrate efforts of governmental agencies in evaluations of status and tre...

218

OXYGEN UPTAKE AND NUTRIENT REGENERATION IN THE PECONIC ESTUARY  

EPA Science Inventory

EXECUTIVE SUMMARY: OXYGEN UPTAKE AND NUTRIENT REGENERATION IN THE PECONIC ESTUARY Rates of oxygen consumption and nutrient regeneration were measured annually throughout the Peconic Estuarine System. Sediment and water column oxygen uptake were measured to determine the potential...

219

Landscape Thresholds and the Condition of Northeastern Estuaries  

EPA Science Inventory

Anthropogenic impacts to northeastern estuaries have been well documented and many researchers have quantified the associations between broad scale human land uses in contributing landscapes and impacted estuarine condition. However, associations alone are not adequate for ident...

220

NEKTON-HABITAT ASSOCIATIONS IN A PACIFIC NORTHWEST (USA) ESTUARY  

EPA Science Inventory

Nekton-habitat associations were determined in Yaquina Bay, Oregon, United States, using a stratified-by-habitat, random, estuary-wide sampling design. Three habitats (intertidal eelgrass [Zostera marina], mud shrimp [Upogebia pugettensis], and ghost shrimp [Neotrypaea californie...

221

Cape Blanco wind farm feasibility study  

NASA Astrophysics Data System (ADS)

The Cape Blanco Wind Farm Feasibility Study investigated the engineering, economic, environmental and meteorological aspects of a proposed 80 MW wind energy project on a 1600-acre site southeast of Cape Blanco, Oregon. Study sponsors evaluated the potential impacts of large (2500 kW) MOD-2 and intermediate (170 kW) FloWind turbines. This volume is a summary of the study and its conclusions.

1987-11-01

222

Sediment transport and trapping in the Hudson River estuary  

Microsoft Academic Search

The Hudson River estuary has a pronounced turbidity maximum zone, in which rapid, short-term deposition of sediment occurs\\u000a during and following the spring freshet. Water-column measurements of currents and suspended sediment were performed during\\u000a the spring of 1999 to determine the rate and mechanisms of sediment transport and trapping in the estuary. The net convergence\\u000a of sediment in the lower

W. Rockwell Geyer; Jonathan D. Woodruff; Peter Traykovski

2001-01-01

223

Attenuation of rare earth elements in a boreal estuary  

NASA Astrophysics Data System (ADS)

This study focuses on attenuation of rare earth elements (REE) when a boreal creek, acidified and loaded with REE and other metals as a result of wetland drainage, empties into a brackish-water estuary (salinity < 6‰). Surface water was collected in a transect from the creek mouth to the outer estuary, and settling (particulate) material in sediment traps moored at selected locations in the estuary. Ultrafiltration, high-resolution ICP-MS and modeling were applied on the waters, and a variety of chemical reagents were used to extract metals from the settling material. Aluminium, Fe and REE transported by the acidic creek were extensively removed in the inner/central estuary where the acidic water was neutralised, whereas Mn was relatively persistent in solution and thus redistributed to particles and deposited further down the estuary. The REE removal was caused by several contemporary mechanisms: co-precipitation with oxyhydroxides (mainly Al but also Fe), complexation with flocculating humic substances and sorption to suspended particles. Down estuary the dissolved REE pool, remaining after removal, was fractionated: the <1 kDa pool became depleted in the middle REE and the colloidal (0.45 ?m-1 kDa) pool depleted in the middle and heavy REE. This fractionation was controlled by the removal process, such that those REE with highest affinity for the settling particles became most depleted in the remaining dissolved pool. Modeling, based on Visual MINTEQ version 3.0 and the Stockholm Humic Model after revision and updating, predicted that the dissolved (<0.45 ?m) REE pool in the estuary is bound almost entirely to humic substances. Acid sulphate soils, the source of the REE and other metals in the creek water, are widespread on coastal plains worldwide and therefore the REE attenuation patterns and mechanisms identified in the studied estuary are relevant for recognition of similar geochemical processes and conditions in a variety of coastal locations.

Åström, Mats E.; Österholm, Peter; Gustafsson, Jon Petter; Nystrand, Miriam; Peltola, Pasi; Nordmyr, Linda; Boman, Anton

2012-11-01

224

Reprint of Water renewal timescales in the Scheldt Estuary  

NASA Astrophysics Data System (ADS)

Using the concepts of the Constituent-oriented Age and Residence time Theory (CART), we compute timescales related to the water renewal in the Scheldt Estuary (The Netherlands/Belgium). Three different timescales are used to better understand and characterize the dynamics of the estuary: the age of the renewing water, the residence time and the exposure time. The residence time is the time taken by a water parcel to leave the estuary for the first time while the exposure time is the total time spent by a water parcel in the estuary including re-entries. The age of a renewing water parcel is defined as the time elapsed since it entered the estuary. The renewing water was split into three types: the water originating from the sea, the water originating from the upstream fresh tidal rivers and the water originating from the different canals and docks connected to the estuary. Every timescale is computed at any time and position by means of the finite-element, unstructured-mesh model SLIM. This results in movies of the timescale fields (shown as Supplementary material), allowing a detailed analysis of their spatial and temporal variabilities. The effect of the M2 tide and the discharge regime (winter, summer or average situation) on the timescales is also investigated.Tidally-averaged timescales vary little over the width of the estuary and hence exhibit a virtually one-dimensional behaviour. However, around these average values, the timescales can vary hugely over a tidal cycle, with amplitudes that significantly depend on the space coordinates. The reason thereof has yet to be elucidated. These results underscore the need for two- or three-dimensional models with high temporal resolution for investigating the dynamics of the Scheldt Estuary.

de Brye, Benjamin; de Brauwere, Anouk; Gourgue, Olivier; Delhez, Eric J. M.; Deleersnijder, Eric

2013-12-01

225

Nutrients, hypoxia and Mass Fishkill events in Tapi Estuary, India  

NASA Astrophysics Data System (ADS)

From 1983 to 2011, dissolved oxygen (DO) conditions in the Tapi Estuary changed from normoxic to hypoxic due to increased and untreated discharge of sewage. Both tidal and day-night variations of DO were best explained by hydrographic factors, sewage pollution and phytoplankton dynamics in upper, middle, lower estuary and the coastal water. Hypoxia/anoxia was associated with low-flow periods due to riverine restrictions and changing in climatic condition. The upper Tapi Estuary becomes anoxic during summer irrespective of tide while the middle estuary was anoxic (<0.2 mg O2 l-1) during post and premonsoon seasons and hypoxic (<2.0 mg O2 l-1) during monsoon season. Differences in the degree of stratification, sewage discharge and flushing accounted for differences in DO. Because of high nutrient concentrations (maximum NO3--N 103.1, NO2--N 26.0, NH4+-N 104.0 and PO43--P 99.0 ?mol l-1), the lower estuary remains DO deficient between 2.0 and 5.0 mg O2 l-1, most of the time. The environmental condition of Tapi Estuary has impacted the coastal water of the Arabian Sea in recent years with fish kills attributed to its hypoxic/anoxic condition. Enhanced concentrations of nutrients and organic matter from indiscriminate discharge of sewage into the Tapi Estuary and restricted flushing as a result of construction of a series of dams in the catchment area of the estuary are the primary factors that have lead to the development of hypoxia.

Ram, Anirudh; Jaiswar, Jiyalal Ram M.; Rokade, M. A.; Bharti, S.; Vishwasrao, C.; Majithiya, D.

2014-07-01

226

Biological effects of anthropogenic contaminants in the San Francisco Estuary  

USGS Publications Warehouse

Concentrations of many anthropogenic contaminants in the San Francisco Estuary exist at levels that have been associated with biological effects elsewhere, so there is a potential for them to cause biological effects in the Estuary. The purpose of this paper is to summarize information about biological effects on the Estuary's plankton, benthos, fish, birds, and mammals, gathered since the early 1990s, focusing on key accomplishments. These studies have been conducted at all levels of biological organization (sub-cellular through communities), but have included only a small fraction of the organisms and contaminants of concern in the region. The studies summarized provide a body of evidence that some contaminants are causing biological impacts in some biological resources in the Estuary. However, no general patterns of effects were apparent in space and time, and no single contaminant was consistently related to effects among the biota considered. These conclusions reflect the difficulty in demonstrating biological effects due specifically to contamination because there is a wide range of sensitivity to contaminants among the Estuary's many organisms. Additionally, the spatial and temporal distribution of contamination in the Estuary is highly variable, and levels of contamination covary with other environmental factors, such as freshwater inflow or sediment-type. Federal and State regulatory agencies desire to develop biological criteria to protect the Estuary's biological resources. Future studies of biological effects in San Francisco Estuary should focus on the development of meaningful indicators of biological effects, and on key organism and contaminants of concern in long-term, multifaceted studies that include laboratory and field experiments to determine cause and effect to adequately inform management and regulatory decisions. ?? 2006 Elsevier Inc. All rights reserved.

Thompson, B.; Adelsbach, T.; Brown, C.; Hunt, J.; Kuwabara, J.; Neale, J.; Ohlendorf, H.; Schwarzbach, S.; Spies, R.; Taberski, K.

2007-01-01

227

Biological effects of anthropogenic contaminants in the San Francisco Estuary.  

PubMed

Concentrations of many anthropogenic contaminants in the San Francisco Estuary exist at levels that have been associated with biological effects elsewhere, so there is a potential for them to cause biological effects in the Estuary. The purpose of this paper is to summarize information about biological effects on the Estuary's plankton, benthos, fish, birds, and mammals, gathered since the early 1990s, focusing on key accomplishments. These studies have been conducted at all levels of biological organization (sub-cellular through communities), but have included only a small fraction of the organisms and contaminants of concern in the region. The studies summarized provide a body of evidence that some contaminants are causing biological impacts in some biological resources in the Estuary. However, no general patterns of effects were apparent in space and time, and no single contaminant was consistently related to effects among the biota considered. These conclusions reflect the difficulty in demonstrating biological effects due specifically to contamination because there is a wide range of sensitivity to contaminants among the Estuary's many organisms. Additionally, the spatial and temporal distribution of contamination in the Estuary is highly variable, and levels of contamination covary with other environmental factors, such as freshwater inflow or sediment-type. Federal and State regulatory agencies desire to develop biological criteria to protect the Estuary's biological resources. Future studies of biological effects in San Francisco Estuary should focus on the development of meaningful indicators of biological effects, and on key organism and contaminants of concern in long-term, multifaceted studies that include laboratory and field experiments to determine cause and effect to adequately inform management and regulatory decisions. PMID:17166494

Thompson, Bruce; Adelsbach, Terry; Brown, Cynthia; Hunt, Jennifer; Kuwabara, James; Neale, Jennifer; Ohlendorf, Harry; Schwarzbach, Steve; Spies, Robert; Taberski, Karen

2007-09-01

228

Sources of nitrogen to estuaries in the United States  

Microsoft Academic Search

The purpose of this study was to quantify the nitrogen (N) inputs to 34 estuaries on the Atlantic and Gulf Coasts of the United\\u000a States. Total nitrogen (TN) inputs ranged from 1 kg N ha?1 yr?1 for Upper Laguna Madre, Texas, to 49 kg N ha?1 yr?1 for Massachusetts Bay, Massachusetts. TN inputs to 11 of the 34 estuaries were

Mark S. Castro; Charles T. Driscoll; Thomas E. Jordan; William G. Reay; Walter R. Boynton

2003-01-01

229

United States Air Force 611th Air Support Group/Civil Engineering Squadron, Elmendorf AFB, Alaska. Remedial investigation and feasibility study: Oliktok Point Radar Installation, Alaska. Volume 1. (Includes appendices a - b)  

SciTech Connect

This report presents the findings of Remedial Investigations and Feasibility Studies at sites located at the Oliktok Point radar installation in northern Alaska. The sites were characterized based on sampling and analyses conducted during Remedial Investigation activities performed during August and September 1993.

NONE

1996-04-15

230

From the utilization point of view, the two approaches seem to United States Air Force 611th Air Support Group/Civil Engineering Squadron, Elmendorf AFB, Alaska. Remedial investigation and feasibility study Point Barrow Radar Installation, Alaska. Final report  

SciTech Connect

This report presents the findings of Remedial Investigations and Feasibility Studies at sites located at the Point Barrow radar installation in northern Alaska. The sites were characterized based on sampling and analyses conducted during Remedial Investigation activities performed during August and September 1993.

Karmi, S.

1996-02-19

231

PCB-resistant diatoms in the Hudson River estuary  

NASA Astrophysics Data System (ADS)

Diatom cells that are resistant, as well as sensitive, to the toxicity of polychlorinated biphenyls (PCB) are widespread throughout the highly polluted Hudson River estuary. A study of the distribution of PCB resistance among populations of the diatoms, Thalassiosira nordenskioldii and Asterionella glacialis, revealed few spatial or temporal patterns for the trait during spring and summer. The number of estuarine clones of A. glacialis tolerant of more than 25 ppb of PCB was greater than twice the number of clones isolated from nearshore waters at Sandy Hook, NJ. This suggests that selection pressure for PCB resistance is greater in the estuary than in the New York Bight apex. If specific sites of selection exist, the mixing of cells within the estuary may be rapid enough to distribute resistant clones throughout the estuary, or the selection process may involve a generalized response to a multitude of pollutants. Several clones of both species tested were not only tolerant of PCB, but were actually enhanced in their growth in the presence of PCB. Such clones were distributed throughout the estuary during both seasons. Selection in the estuary favours not only resistant strains of diatoms, but forms that may utilize organic pollutants.

Cosper, Elizabeth M.; Wurster, Charles F.; Bautista, Mark F.

1988-02-01

232

NEWSLETTER OF THE PARTNERSHIP FOR THE DELAWARE ESTUARY: A NATIONAL ESTUARY PROGRAM VOLUME 20 ISSUE 5 SUMMER 2010  

E-print Network

Updates 3 Estuary News Turns 20, Wins Award 3 Act Seeks to Provide Funding, Coordination for Basin 3 "Fracking" Delayed to Ensure Clean Water 7 Electricity Lines: Coming to a Watershed Near You 9 Wind Power

Firestone, Jeremy

233

Northern New Mexico regional airport market feasibility  

SciTech Connect

This report is about the market for airline travel in northern New Mexico. Interest in developing a northern New Mexico regional airport has periodically surfaced for a number of years. The New Mexico State Legislature passed a memorial during the 1998 Second Session calling for the conduct of a study to determine the feasibility of building a new regional airport in NNM. This report is a study of the passenger market feasibility of such an airport. In addition to commercial passenger market feasibility, there are other feasibility issues dealing with siting, environmental impact, noise, economic impact, intermodal transportation integration, region-wide transportation services, airport engineering requirements, and others. These other feasibility issues are not analyzed in any depth in this report although none were discovered to be show-stoppers as a by-product of the authors doing research on the passenger market itself. Preceding the need for a detailed study of these other issues is the determination of the basic market need for an airport with regular commercial airline service in the first place. This report is restricted to an in-depth look at the market for commercial passenger air service in NNM. 20 figs., 8 tabs.

Drake, R.H.; Williams, D.S.

1998-06-01

234

A feasibility analysis of three concepts for airplane stall deterrence  

E-print Network

was conducted to determine the feasibility of three approaches to develop an airplane stall deterrent device. The static longitudinal stability and control characteristics of a typical light single-engine and twin-engine airplane were obtained and modi fied... cases resulted in a stall proof airplane. It was found that the tab was an effective stall deterrent device on the light single-engine airplane. However, the tab stall deterrent device resulted in a degradation of the stick force gradient in several...

Gallaway, Charles Ray

2012-06-07

235

Seasonal dynamics of meiofauna in a South African temporarily open\\/closed estuary (Mdloti Estuary, Indian Ocean)  

Microsoft Academic Search

One hundred and eighty-four of the 250 estuaries in South Africa are currently classified as temporarily open\\/closed and close off from the sea during the dry season, under low river inflow. The subtropical Mdloti Estuary, on the KwaZulu-Natal north coast, is one of these systems and hardly any information is available on its meiofauna. The abundance, biomass, composition, and grazing

Christian Nozais; Renzo Perissinotto; Guglielmo Tita

2005-01-01

236

Nitinol engine development  

Microsoft Academic Search

The objective of this project is to determine the feasibility of applying the shape-memory effect in certain intermetallic compounds (particularly ''55 Nitinol'') to the conversion of low temperature heat energy to mechanical work by means of solid state heat engines. A primary milestone is the development of a prototype Nitinol engine on a scale suitable for powering a moderate-size residential

M. Wahlig; R. Banks; R. Kopa; H. Mohamed

1978-01-01

237

Engineering tubular bone constructs  

Microsoft Academic Search

Cell-sheet techniques have been proven effective in various soft tissue engineering applications. In this experiment, we investigated the feasibility of bone tissue engineering using a hybrid of mesenchymal stem cell (MSC) sheets and PLGA meshes. Porcine MSCs were cultured to a thin layer of cell sheets via osteogenic induction. Tube-like long bones were constructed by wrapping the cell sheet on

Fulin Chen; Yefang Zhou; Saey Tuan Barnabas; Maria Ann Woodruff; Dietmar W. Hutmacher

2007-01-01

238

Methane and nitrous oxide emissions from a subtropical estuary (the Brisbane River estuary, Australia).  

PubMed

Methane (CH4) and nitrous oxide (N2O) are two key greenhouse gases. Their global atmospheric budgeting is, however, flout with challenges partly due to lack of adequate field studies determining the source strengths. Knowledge and data limitations exist for subtropical and tropical regions especially in the southern latitudes. Surface water methane and nitrous oxide concentrations were measured in a subtropical estuarine system in the southern latitudes in an extensive field study from 2010 to 2012 and water-air fluxes estimated using models considering the effects of both wind and flow induced turbulence. The estuary was found to be a strong net source of both CH4 and N2O all-year-round. Dissolved N2O concentrations ranged between 9.1 ± 0.4 to 45.3 ± 1.3 nM or 135 to 435% of atmospheric saturation level, while CH4 concentrations varied between 31.1 ± 3.7 to 578.4 ± 58.8 nM or 1210 to 26,430% of atmospheric saturation level. These results compare well with measurements from tropical estuarine systems. There was strong spatial variability with both CH4 and N2O concentrations increasing upstream the estuary. Strong temporal variability was also observed but there were no clear seasonal patterns. The degree of N2O saturation significantly increased with NOx concentrations (r(2)=0.55). The estimated water-air fluxes varied between 0.1 and 3.4 mg N2O m(-2)d(-1) and 0.3 to 27.9 mg CH4 m(-2)d(-1). Total emissions (CO2-e) were N2O (64%) dominated, highlighting the need for reduced nitrogen inputs into the estuary. Choice of the model(s) for estimation of the gas transfer velocity had a big bearing on the estimated total emissions. PMID:24333994

Musenze, Ronald S; Werner, Ursula; Grinham, Alistair; Udy, James; Yuan, Zhiguo

2014-02-15

239

REP Concept Feasibility Study  

NASA Technical Reports Server (NTRS)

Radioisotope Electric Propulsion (REP) may have the potential to provide certain advantages, over conventional chemical propulsion, for outer planetary exploration involving small bodies and long term investigations for medium class missions requiring power comparable to past outer planetary exploration missions. This paper describes a study that investigates the concept s feasibility by performing a preliminary conceptual design of an REP-based spacecraft for a design reference mission. The mission utilizes a spacecraft with a radioisotope power supply less than one kilowatt while operating for a minimum of 10-years. A key element of the REP spacecraft is to ensure sustained science return by orbiting or flying in formation with selected targets. Utilizing current and impending technological advances, this study finds that at a conceptual design level a small body REP orbiter/explorer appears to be feasible for the design reference mission selected for this study.

Edwards, Daryl A.; Ensworth, Clinton B. F.; Goodnight, Thomas W.; Sheehe, Charles J.; Wiersma, Stephen C.; Adamsen, Paul B., II; Frank, Larry

2004-01-01

240

Ceramic Automotive Stirling Engine Program  

SciTech Connect

The Ceramic Automotive Stirling Engine Program evaluated the application of advanced ceramic materials to an automotive Stirling engine. The objective of the program was to evaluate the technical feasibility of utilizing advanced ceramics to increase peak engine operating temperature, and to evaluate the performance benefits of such an increase. Manufacturing cost estimates were also developed for various ceramic engine components and compared with conventional metallic engine component costs.

Not Available

1986-08-01

241

Ceramic automotive Stirling engine program  

NASA Technical Reports Server (NTRS)

The Ceramic Automotive Stirling Engine Program evaluated the application of advanced ceramic materials to an automotive Stirling engine. The objective of the program was to evaluate the technical feasibility of utilizing advanced ceramics to increase peak engine operating temperature, and to evaluate the performance benefits of such an increase. Manufacturing cost estimates were also developed for various ceramic engine components and compared with conventional metallic engine component costs.

1986-01-01

242

CLASSIFYING OREGON ESTUARIES BY HABITAT: ANALYSIS OF EXISTING DATA AND A PROPOSAL FOR A PILOT STUDY  

EPA Science Inventory

Because many estuarine resources are linked to benthic habitats, classification of estuaries by habitat types may prove a relevant approach for grouping estuaries with similar ecological values and vulnerability to landscape alterations. As a first step, we evaluated whether pub...

243

76 FR 23306 - Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Management...  

Federal Register 2010, 2011, 2012, 2013

...Incidental to Specified Activities; Russian River Estuary Management Activities AGENCY...activities conducted at the mouth of the Russian River, Sonoma County, California. DATES...April 1 to December 31, 2010; and Russian River Estuary Outlet Channel Adaptive...

2011-04-26

244

77 FR 24471 - Takes of Marine Mammals Incidental to Specified Activities; Russian River Estuary Management...  

Federal Register 2010, 2011, 2012, 2013

...Incidental to Specified Activities; Russian River Estuary Management Activities AGENCY...activities conducted at the mouth of the Russian River, Sonoma County, California. DATES...July 2009 to December 2011); Russian River Estuary Outlet Channel Adaptive...

2012-04-24

245

A DATA SYSTEM FOR INTEGRATING DATA FROM LANDSCAPES, STREAMS AND ESTUARIES  

EPA Science Inventory

Estuaries are natural integrators of substances and processes that occur internally and externally (watersheds, ocean, atmosphere). Watershed activities that contribute fresh water, nutrients, contaminants, and suspended solids have a strong effect on the health of estuaries. Res...

246

Evaluating Cumulative Ecosystem Response to Restoration Projects in the Lower Columbia River and Estuary, 2009  

SciTech Connect

This is the sixth annual report of a seven-year project (2004 through 2010) to evaluate the cumulative effects of habitat restoration actions in the lower Columbia River and estuary (LCRE). The project, called the Cumulative Effects Study, is being conducted for the U.S. Army Corps of Engineers Portland District (USACE) by the Marine Sciences Laboratory of the Pacific Northwest National Laboratory (PNNL), the Pt. Adams Biological Field Station of the National Marine Fisheries Service (NMFS), the Columbia River Estuary Study Taskforce (CREST), and the University of Washington. The goal of the Cumulative Effects Study is to develop a methodology to evaluate the cumulative effects of multiple habitat restoration projects intended to benefit ecosystems supporting juvenile salmonids in the 235-km-long LCRE. Literature review in 2004 revealed no existing methods for such an evaluation and suggested that cumulative effects could be additive or synergistic. From 2005 through 2009, annual field research involved intensive, comparative studies paired by habitat type (tidal swamp versus marsh), trajectory (restoration versus reference site), and restoration action (tidegate replacement vs. culvert replacement vs. dike breach).

Johnson, Gary E.; Diefenderfer, Heida L.; Borde, Amy B.; Bryson, Amanda J.; Cameron, April; Coleman, Andre M.; Corbett, C.; Dawley, Earl M.; Ebberts, Blaine D.; Kauffman, Ronald; Roegner, G. Curtis; Russell, Micah T.; Silva, April; Skalski, John R.; Thom, Ronald M.; Vavrinec, John; Woodruff, Dana L.; Zimmerman, Shon A.

2010-10-26

247

Modelling of cohesive sediment dynamics in tidal estuarine systems: Case study of Tagus estuary, Portugal  

NASA Astrophysics Data System (ADS)

Cohesive sediment dynamics in estuarine systems is a major issue in water quality and engineering problems. Numerical models can help to assess the complex dynamics of cohesive sediments, integrating the information collected in monitoring studies. Following a numerical approach we investigated the main factors that influence the cohesive sediment dynamics in an estuarine system composed of large mudflats (Tagus estuary, Portugal). After a spin up period of the bottom layer and considering the combined effect of waves and currents on the bottom shear stress, the dynamics of cohesive sediment during the fortnightly and daily erosion-sedimentation cycle was properly reproduced by the model. The results of cohesive suspended sediments were validated with data from sixteen monitoring stations located along the estuary and turbidity data measured by two multiparametric probes. The hydrodynamics were previously validated by harmonic analysis and with ADCP data. Although tidal currents are the major cause of cohesive sediment erosion, the results suggest that wind waves also play an important role. The simulated sediment mass involved in the fortnightly tidal cycle was in the same order of magnitude of the annual load from the rivers, as observed in previous studies based on field data.

Franz, G.; Pinto, L.; Ascione, I.; Mateus, M.; Fernandes, R.; Leitão, P.; Neves, R.

2014-12-01

248

Estuaries of the northeastern United States: Habitat and land use signatures  

Microsoft Academic Search

Geographic signatures are physical, chemical, biotic, and human-induced characteristics or processes that help define similar\\u000a or unique features of estuaries along latitudinal or geographic gradients. Geomorphologically, estuaries of the northeastern\\u000a U.S., from the Hudson River estuary and northward along the Gulf of Maine shoreline, are highly diverse because of a complex\\u000a bedrock geology and glacial history. Back-barrier estuaries and lagoons

Charles T. Roman; Norbert Jaworski; Frederick T. Short; Stuart Findlay; R. Scott Warren

2000-01-01

249

A comparative study of carbon dioxide degassing in river- and marine-dominated estuaries  

Microsoft Academic Search

The partial pressure of carbon dioxide (pCO2), concentration of total dissolved inorganic carbon, and total alkalinity were measured at both high tide and low tide in the surface water of three Georgia estuaries from September 2002 to May 2004. Of the three estuaries, Sapelo and Doboy Sounds are marine-dominated estuaries, while Altamaha Sound is a river-dominated estuary. During all sampling

Li-Qing Jiang; Wei-Jun Cai; Yongchen Wang

2008-01-01

250

Sediment balance of intertidal mudflats in a macrotidal estuary  

NASA Astrophysics Data System (ADS)

Intertidal area contributes widely to fine-grained sediment balance in estuarine environments. Their sedimentary dynamics is controlled by several forcing parameters including tidal range, river flow and swell, affected by human activities such as dredging, construction or vessels traffic leading to modify sediment transport pattern. Although the estuarine hydrodynamics is well documented, the link between forcing parameters and these sedimentary processes is weakly understood. One of the main reasons is the difficulty to integrate spatial (from the fluvial to the estuary mouth) and temporal (from swell in seconds to pluriannual river flow variability) patterns. This study achieved on intertidal mudflats distributed along the macrotidal Seine estuary (France) aims (i) to quantify the impact of forcing parameters on each intertidal area respect to its longitudinal position in the estuarine system and (ii) to assess the fine-grained sediment budget at estuarine scale. The Seine estuary is a macrotidal estuary developed over 160 km up the upstream limit of tidal wave penetration. With an average river flow of 450m3.s-1, 80% of the Suspended Particles Matter (SPM) annual flux is discharged during the flood period. In the downstream part, the Seine estuary Turbidity Maximum (TM) is the SPM stock located near the mouth. During their transfer toward the sea, the fine particles can be trapped in (i) the intertidal mudflats; preferential areas characterized by low hydrodynamics and generally sheltered of the tidal dominant flow, the main tidal current the Seine River and (ii) the TM. The Seine estuary is an anthropic estuary in order to secure navigation: one consequence of these developments is the tidal bore disappearance. Along the macrotidal Seine estuary hydrodynamics features and sedimentary fluxes were followed during at least 1 year using respectively Acoustic Doppler Velocimeter, Optical BackScatter and altimeter. Results in the fluvial estuary enhance the role of hydrological cycle that lead to (i) an increased mean water level and (ii) provide SPM from the continental area. This feature leads to significant accretion over intertidal area. In the middle and marine estuary the TM is the main SPM supplier. In these parts of the estuary deposition over these intertidal area is driven by (i) tidal cycle in particular fortnightly cycle link to maximum TM resuspension during (strongest) spring tide and (ii) TM location controlled by river inflow that varies following an annual and inter-annual variability. Outside sedimentation period, the erosion is driven by the combination of (i) progressive erosion driven by fortnightly cycle and (ii) sudden erosion controlled either by wave or boat generated waves respectively at the mouth and in the middle/upper estuary. This last is reinforced by the rheological characteristics of deposit that correspond to fluid/low consolidated mud. During most of the year, the Seine estuary mudflats record an erosion pattern. Significant and intensive sedimentation only occurs few days per year. This pattern is linked to highly variable hydrodynamics conditions (bottom shear stress ranging from 0.5 to 5 N.m-2) that control the sediment supply availability. In this infilling macrotidal anthropized system mudflats are close to equilibrium with an annual rate ranging between +/- 5cm.yrs-1: they act as temporal storage area of fined-grained sediments.

lafite, R.; Deloffre, J.; Lemoine, M.

2012-12-01

251

Observations of Floc Sizes in a Muddy Estuary  

NASA Astrophysics Data System (ADS)

Measurements are presented of median floc diameters and associated environmental data over spring-tide tidal cycles at two stations in the muddy Tamar Estuary, UK, for winter, spring and summer conditions. The particulate organic carbon and particulate total carbon contents of mudflats and SPM (suspended particulate matter) at the stations, together with other evidence, indicates that much of the SPM was derived from mud sources that were located between the two stations during winter and spring, and from very mobile sediment sources in the upper estuary during summer. Observed in-situ median floc sizes varied widely, from <50 to >500 ?m and rapid settling of particles close to HW and LW (high and low water) left only the smaller flocs in suspension. Time-series of depth-averaged median floc sizes generally were most closely, positively, correlated with depth-averaged SPM concentrations. Floc diameters tended to reach maximum median sizes near the time when SPM concentrations were highest. These high concentrations were in turn largely generated by resuspension of sediment during the fastest current speeds. Although such correlations may have arisen because of SPM-driven floc growth - despite fast tidal currents - there is also the possibility that tough aggregates were eroded from the intertidal mudflats and mudbanks. Although a hypothesis, such large aggregates of fine sediment may have resulted from the binding together of very fine bed particles by sticky extracellular polymeric substances (EPS) coatings, produced by benthic diatoms and by other biologically-mediated activity. A rapid reduction of SPM occurred at the up-estuary station within 2.5 h of HW on the flood, when decelerating currents were still relatively fast. It appears that at least two processes were at work: localised settling of the largest flocs and up-estuary transport in which large flocs were transported further into the estuary before settling into the Tamar's ETM (estuarine turbidity maximum) over the HW-slack period. Up-estuary advection of large flocs and their eventual settling would place the down-estuary edge of the ETM above the upper-estuary station during summer, spring-tide conditions. This position of the ETM was observed close to HW during longitudinal surveys of the estuary.

Uncles, R. J.; Bale, A. J.; Stephens, J. A.; Frickers, P. E.; Harris, C.

2010-04-01

252

Dynamics of intertidal flats in the Loire estuary  

NASA Astrophysics Data System (ADS)

Tidal flats form at the edges of many tidal estuaries, and are found in broad climatic regions. Their evolution plays a fundamental role in maintaining the morphodynamic equilibrium of an estuary. The Loire estuary is one of the largest macrotidal systems of the french atlantic coast. Since 200 years, its geometry has been drastically modified through channeling, deepening, embanking, infilling of secondary channels, etc. These works altered many intertidal areas. In the recent years, efforts for the rectification of the morphology have been made in order to restore the ecology of the estuary. In this context, it is crucial to better understand the dynamics of intertidal flats, still poorly understood in this estuary. The aim of this work is to analyse a series of original observations conducted for the first time in two intertidal flats of the central Lore estuary between 2008 and 2010. The tidal flats are situated in the northern bank, at 12 and 17 km upstream from the mouth respectively. Six Altus altimeters were deployed at two cross shore transects, measuring continuously and at a high-frequency bed altimetry and water level, providing information on tide and waves. At the semi-diurnal tidal scale, the surficial sediment of intertidal flats is permanently mobilized. Altimetry variations are low, and their amplitude varies as a function of tides and river flow. At the scale of several months, the sedimentation is controlled by the position of the turbidity maximum (and therefore by the river flow) and also by the tidal amplitude. During low river flow periods, altimetry variations are only due to tidal cycles. During decaying tides, suspended sediment settle mainly on the lower part of the tidal flats, forming fluid mud layers of several cm thick, which can consolidate rapidly; under rising tides, the increasing of tidal currents promotes erosion. During periods of high river flow, the turbidity maximum shifts to the lower estuary. The higher suspended sediment concentration increases deposition and erosion rates, especially in the lower parts of the flats, where continuous sedimentary accretion is favoured by the proximity of the channel. During this period, reinforcement of current veolocities limits deposition in the central and high portion of the flats, where erosion is enhanced. The first rivers floods remove fluid mud in the upper estuary, previously deposited during the dry season, which is transported seawards. The transported suspended sediment settles massively in the lower parts of the flats and in the channels. The deposited mud is eroded a few days later. These results provide useful information to better understand the dynamics of the Loire estuary, as well as they give in situ data to be compared with numerical modelling.

Kervella, Stephane; Sottolichio, Aldo; Bertier, Christine

2014-05-01

253

Proliferation of dinoflagellates in Kochi estuary, Kerala.  

PubMed

Phytoplankton community structure and dynamics of Kochi estuary (bar mouth) have been studied seasonally. Three seasonal samplings namely pre-monsoon, monsoon and post-monsoon were made, and a wide variation was observed in phytoplankton community with respect to nutrients and other physicochemical parameters. Contrary to other seasons, dinoflagellate cell density increased during pre-monsoon season though species diversity was less pronounced (D > 0.15). Peridinium oceanicum was the dominant dinoflagellate during pre-monsoon season. Significant fluctuation in three principal nutrients namely total nitrogen, total phosphorous and silicate were observed during pre-monsoon (TP < 1.8 micromol l(-1), TN > 40 micromol l(-1) and SiO4 < 20 micromol l(-1)) season as compared to monsoon season (TP > 3.20 micromol l(-1), TN < 20 micromol l(-1) and SiO4 > 27 micromol l(-1)). Salinity values were also found to be high during pre-monsoon ( > 25 psu). Study suggests that variation in salinity and nutrient concentration during transition of seasons could result in succession of species, thereby causing change in phytoplankton community structure. High salinity and nitrogen values along with low values of silicate and phosphorous resulted in proliferation of dinoflagellates during pre-monsoon season. PMID:25204062

Kumar, M Ratheesh; Vishnu, S Raj; Sudhanandh, V S; Faisal, A K; Shibu, R; Vimexen, V; Ajmal, K; Aneesh, K S; Antony, Sibin; Krishnan, Anoop K

2014-09-01

254

Dissolved Humic Matter in Arctic Estuaries  

NASA Astrophysics Data System (ADS)

As part of the German-Russian bilateral SIRRO(Siberian River Runoff)-project we studied the distribution of dissolved humic matter isolated by XAD-8 in the estuarine waters of the Ob and Yenisei rivers. The relative contributions of humic matter carbon to total DOC decreased from 61-77 percent in the river freshwater endmember to 35-40 percent in the marine waters of the open Kara Sea at salinities 33 psu. Humic carbon mixed conservatively in the Yenisei and non-conservatively in the Ob, where partial removal was indicated in the low salinity range. Changes in the relative contribution of humic matter to different molecular weight classes of DOM (ultrafiltration cutoffs 150 KDa, 450 KDa, 800 KDa) were studied along the salinity gradient in the Yenisei. High molecular weight DOM is relatively enriched in humics in fresh-water compared to sea-water HMW-DOM. Low molecular weight DOM is realtively enriched in humics in sea-water compared to fresh-water LMW-DOM. Throughout the estuary humic matter is depleted in 13C and nitrogen compared to total DOM, reflecting a dominant soil source. We estimate an annual input of 5 Tg humic matter carbon by the two rivers into the Kara Sea.

Spitzy, A.; Koehler, H.; Ertl, S.

2002-12-01

255

Sedimentation of river-transported particles in the Öre estuary, northern Sweden  

Microsoft Academic Search

Sedimentation of river transported particles in the Öre Estuary was studied during spring flow (April–May, 1989). River input was calculated as the product of discharge and particle concentration in the river water. The concentration of suspended matter in the estuary water was determined with a light-scattering probe at 25 depth profiles throughout the estuary. The sedimentation was measured using sediment

Louise Malmgren; Lars Brydsten

1992-01-01

256

Three-dimensional modeling of hydrodynamic processes in the St. Lucie Estuary  

Microsoft Academic Search

Comparing with the studies on large estuarine systems, such as the Chesapeake Bay and the San Francisco Bay, the processes of stratification and transport in small and shallow estuaries are relatively less studied. The St. Lucie Estuary (SLE) is a riverine estuary located on the east coast of south Florida. It is small and shallow, with mean depth of 2.4m.

Zhen-Gang Ji; Guangdou Hu; Jian Shen; Yongshan Wan

2007-01-01

257

Late-stage estuary infilling controlled by limited accommodation space in the Hudson River  

E-print Network

Late-stage estuary infilling controlled by limited accommodation space in the Hudson River A subsurface stratigraphy of the broad Tappan Zee­ Piermont region of the Hudson River Estuary. We identify, but dominated by nondeposition or erosion. Limited accommodation space in the Hudson River Estuary may

Carbotte, Suzanne

258

Submersed Vegetation as Habitat for Invertebrates in the Hudson River Estuary  

E-print Network

Submersed Vegetation as Habitat for Invertebrates in the Hudson River Estuary DAVID L. STRAYER the Hudson River estuary to assess the importance of plant beds in providing habitat for macroinvertebrates of submersed vegetation in the Hudson River estuary led to a program to map the vegetation and assess its

Berkowitz, Alan R.

259

Man-made radionuclides and sedimentation in the Hudson River Estuary  

Microsoft Academic Search

Recently deposited fine-grained sediments in the Hudson River estuary contain radionuclides from global fallout produced by atmospheric bomb tests as well as from low-level releases of a local nuclear reactor. Accumulation rates of these nuclides are dependent on rates of sediment deposition and vary with location in the estuary by more than two orders of magnitude. Within the Hudson estuary,

H. J. Simpson; C. R. Olsen; R. M. Trier; S. C. Williams

1976-01-01

260

Complex circulation patterns in the Hudson River Estuary as revealed by bed form patterns  

Microsoft Academic Search

High-resolution multibeam bathymetry and backscatter has been collected from over 75 river miles of the Hudson River Estuary in water depths greater than 5 m using an EM3000 multibeam echosounder. The Hudson River Estuary is a partially mixed estuary near the ocean but a tidal river elsewhere. These data show a wide range of bed forms, including natural features such

R. D. Flood

2002-01-01

261

Dissolved organic carbon in the freshwater tidal reaches of the Schelde estuary  

Microsoft Academic Search

To unravel the factors that regulate DOC dynamics in the freshwater tidal reaches of the Schelde estuary, DOC concentration and biodegradability were monitored in the upper Schelde estuary and its major tributaries. Although the Schelde estuary possesses a densely populated and industrialized catchment, our data suggest that the bulk of DOC in the freshwater tidal reaches is not derived from

Koenraad Muylaert; Renaat Dasseville; Loreto De Brabandere; Frank Dehairs; Wim Vyverman

2005-01-01

262

NOAA's National Ocean Service: Estuaries NOS home NOS education home site index  

E-print Network

water draining from the land and salty seawater. Estuaries are some of the most productive ecosystems in the world. Many animal species rely on estuaries for food and as places to nest and breed. Humans communities also rely on estuaries for food, recreation and jobs. Of the 32 largest cities in the world, 22

263

Zonation of intertidal macrobenthos in the estuaries of Schelde and Ems  

Microsoft Academic Search

Based on data, collected in 1980–1990, the intertidal benthic macrofauna of the Schelde and Ems estuaries was compared. The spatial occurrence of the benthic macrofauna along the salinity gradient, including the freshwater tidal area was emphasized. Both estuaries appeared to have a very similar species composition, especially at genus level. The higher number of species observed in the Schelde estuary

T. Ysebaert; P. Meire; J. Coosen; K. Essink

1998-01-01

264

San Francisco Estuary Regional Monitoring Program for Trace Substances Report of the 2003 Program Review  

E-print Network

San Francisco Estuary Regional Monitoring Program for Trace Substances Report of the 2003 Program Review REGIONAL MONITORING PROGRAM FOR TRACE SUBSTANCES in the SAN FRANCISCO ESTUARY Mr. Robert Berger Dr Review REGIONAL MONITORING PROGRAM FOR TRACE SUBSTANCES in the SAN FRANCISCO ESTUARY Panel: Mr. Robert

265

Degree of Fragmentation Affects Fish Assemblage Structure in Andros Island (Bahamas) Estuaries  

Microsoft Academic Search

We used underwater visual census (UVC) to characterize fish assemblages among estuaries with different degrees of fragmentation on Andros Island, Bahamas. Estuaries were classified a priori into four fragmentation categories: totally fragmented (no surface water connectivity to the ocean), partially fragmented, minimally fragmented, and unfragmented (unimpeded surface water connectivity through the estuary to the ocean). Visual surveys (n = 159)

CRAIG A. LAYMAN; D. ALBREY ARRINGTON; R. B RIAN LANGERHANS; BRIAN REED SILLIMAN

2004-01-01

266

Engineering Electrical &  

E-print Network

Computer Engineering Electrical & Electronic Engineering Mechatronics Engineering Mechanical Engineering Civil Engineering Natural Resources Engineering Forest Engineering Chemical & Process Engineering ELECTIVE 2 Required Engineering Intermediate Year 2011 Eight Required Courses Chart: 120 points College

Hickman, Mark

267

Engineering Electrical &  

E-print Network

Computer Engineering Electrical & Electronic Engineering Mechatronics Engineering Mechanical Engineering Civil Engineering Natural Resources Engineering Forest Engineering Chemical & Process Engineering ELECTIVE 2 Required Engineering Intermediate Year 2012 Eight Required Courses Chart: 120 points College

Hickman, Mark

268

An engine air-brake integration study  

E-print Network

The feasibility of operating an engine air-brake (EAB) integrated with a pylon duct bifurcation in a realistic aircraft engine environment has been analyzed. The EAB uses variable exit guide vanes downstream of a high ...

Mulchandani, Hiten

2011-01-01

269

Engineering Engineering Education  

E-print Network

E School of Engineering Engineering Education in a University Setting 292 Degree Programs in Engineering 294 Special Programs 296 Honors 298 Academic Regulations 300 Courses of Study 305 Engineering of Engineering is the largest and oldest private engineering school in the South. Classes offering engineering

Simaan, Nabil

270

Tidal and river discharge forcing upon water and sediment circulation at a rock-bound estuary (Guadiana estuary, Portugal)  

NASA Astrophysics Data System (ADS)

The relative impacts of tidal (neap, spring) and river discharge (including a flood event) forcing upon water and sediment circulation have been examined at the rock-bound Guadiana estuary. Near-bed and vertical profiles of current, salinity, turbidity, plus surface suspended sediment concentrations (SSC, at some stations only), were collected at the lower and central/upper estuary during tidal and fortnightly cycles. In addition, vertical salinity and turbidity profiles were collected around high and low water along the estuary. Tidal asymmetry produced faster currents on the ebb than on the flood, especially at the mouth. This pattern of seaward current dominance was enhanced with increasing river flow, due to horizontal advection that was confined within the narrow estuarine channel. The freshwater inputs and, at a degree less, the tidal range controlled the vertical mixing and stratification importance. Well-mixed (spring) and partially stratified (neap) conditions alternated during periods of low river flows, with significant intratidal variations induced by tidal straining (especially at the partially stratified estuary). Highly stratified conditions developed with increasing river discharge. Intratidal variability in the pycnocline depth and thickness resulted from current shear during the ebb. A salt wedge with tidal motion was observed at the lower estuary during the flood event. Depending on the intensity of turbulent mixing, the residual water circulation was dominantly controlled either by tidal asymmetry or gravitational circulation. The SSC was governed by cyclical local processes (resuspension, deposition, mixing, advection) driven by the neap-spring fluctuations in tidal current velocities. More, intratidal variability in stratification indicated the significance of tidal pumping at the partially and highly stratified estuary. The estuary turbidity maximum (ETM) was enhanced with increasing current velocities, and displaced downstream during periods of high river discharge. During the flood event, the ETM was expelled out of the estuary, and the SSC along the estuary was controlled by the sediment load from the drainage basin. Under these highly variable river flow conditions, our observations suggest that sand is exported to the nearshore over the long-term (>years).

Garel, E.; Pinto, L.; Santos, A.; Ferreira, Ó.

2009-09-01

271

A review of solar-powered Stirling engines and low temperature differential Stirling engines  

Microsoft Academic Search

This article provides a literature review on solar-powered Stirling engines and low temperature differential Stirling engines technology. A number of research works on the development of Stirling engines, solar-powered Stirling engines, and low temperature differential Stirling engines is discussed. The aim of this review is to find a feasible solution which may lead to a preliminary conceptual design of a

Bancha Kongtragool; Somchai Wongwises

2003-01-01

272

Impact of the Clean Water Act on the levels of toxic metals in urban estuaries: The Hudson River estuary revisited  

SciTech Connect

To establish the impact of the Clean Water Act on the water quality of urban estuaries, dissolved trace metals and phosphate concentrations were determined in surface waters collected along the Hudson River estuary between 1995 and 1997 and compared with samples collected in the mid-1970s by Klinkhammer and Bender. The median concentrations along the estuary have apparently declined 36--56% for Cu, 55--89% for Cd, 53--85% for Ni, and 53--90% for Zn over a period of 23 years. These reductions appear to reflect improvements in controlling discharges from municipal and industrial wastewater treatment plants since the Clean Water Act was enacted in 1972. In contrast, levels of dissolved nutrients (PO{sub 4}) have remained relatively constant during the same period of time, suggesting that wastewater treatment plant improvements in the New York/New Jersey Metropolitan area have not been as effective at reducing nutrient levels within the estuary. While more advanced wastewater treatment could potentially reduce the levels of Ag and PO{sub 4} along the estuary, these improvements would have a more limited effect on the levels of other trace metals.

Sanudo-Wilhelmy, S.A.; Gill, G.A.

1999-10-15

273

Does boat traffic cause displacement of fish in estuaries?  

PubMed

Estuaries are increasingly under threat from a variety of human impacts. Recreational and commercial boat traffic in urban areas may represent a significant disturbance to fish populations and have particularly adverse effects in spatially restricted systems such as estuaries. We examined the effects of passing boats on the abundance of different sized fish within the main navigation channel of an estuary using high resolution sonar (DIDSON). Both the smallest (100-300 mm) and largest (>501 mm) size classes had no change in their abundance following the passage of boats. However, a decrease in abundance of mid-sized fish (301-500 mm) occurred following the passage of boats. This displacement may be attributed to a number of factors including noise, bubbles and the rapidly approaching object of the boat itself. In highly urbanised estuarine systems, regular displacement by boat traffic has the potential to have major negative population level effects on fish assemblages. PMID:23938471

Becker, Alistair; Whitfield, Alan K; Cowley, Paul D; Järnegren, Johanna; Næsje, Tor F

2013-10-15

274

Water Injection Feasibility for Boeing 747 Aircraft  

NASA Technical Reports Server (NTRS)

Can water injection be offered at a reasonable cost to large airplane operators to reduce takeoff NO( sub x) emissions? This study suggests it may be possible. This report is a contract deliverable to NASA Glenn Research Center from the prime contractor, The Boeing Commercial Airplane Company of Seattle, WA. This study was supported by a separate contract to the Pratt & Whitney Engine Company of Hartford, CT (contract number NNC04QB58P). Aviation continues to grow and with it, environmental pressures are increasing for airports that service commercial airplanes. The feasibility and performance of an emissions-reducing technology, water injection, was studied for a large commercial airplane (e.g., Boeing 747 with PW4062 engine). The primary use of the water-injection system would be to lower NOx emissions while an important secondary benefit might be to improve engine turbine life. A tradeoff exists between engine fuel efficiency and NOx emissions. As engines improve fuel efficiency, by increasing the overall pressure ratio of the engine s compressor, the resulting increased gas temperature usually results in higher NOx emissions. Low-NO(sub x) combustors have been developed for new airplanes to control the increases in NO(sub x) emissions associated with higher efficiency, higher pressure ratio engines. However, achieving a significant reduction of NO(sub x) emissions at airports has been challenging. Using water injection during takeoff has the potential to cut engine NO(sub x) emissions some 80 percent. This may eliminate operating limitations for airplanes flying into airports with emission constraints. This study suggests an important finding of being able to offer large commercial airplane owners an emission-reduction technology that may also save on operating costs.

Daggett, David L.

2005-01-01

275

Human Impact on Estuaries: A Terrible Spill in Grand Bay  

NSDL National Science Digital Library

In this activity, learners make a model of a pollution spill that occurred at Bangs Lake in Mississippi and measure water quality parameters in their model. Learners then study the actual spill, analyzing various forms of data to determine the date of the spill and identify how the spill changed water quality parameters in the estuary during and after the spill. Learners speculate on how various life forms in the estuary were affected. Finally, learners produce a timeline of the spill event, with recommendations to the state Department of Environmental Quality about how to prevent large-scale pollution spills like this in the future.

Terc; National Oceanic and Atmospheric Administration (NOAA)

2012-07-24

276

Environmental management of a highly impacted, urbanized tropical estuary: rehabilitation and restoration  

NASA Astrophysics Data System (ADS)

The principles of the dynamics and interrelationships within the dominant subtropical and tropical Caribbean seagrass community have been studied previously before, during, and after impact. From these and scores of observations of damage and recovery patterns in Thalassia ecosystems, a sense of management recovery strategy has emerged. Artificial restoring of Thalassia testudinum seeds into areas cut off from stock (fruit, seeds) appeared feasible on a large scale after the Turkey Point (Biscayne Bay, Miami, Florida) restoration and test sampling throughout North Biscayne Bay. Two large-scale seeding attempts were made; after 11 months they compared favorably with Turkey Point specimens with regard to growth parameters, despite the turbidity and other persistent pollution. Thus, the possible areas in which Thalassia seed restoration can be used has increased to include estuaries of multiple impact still in various stages of recovery after physical and sewage pollution. This technique should be especially useful to “developing” nations where important nearshore fisheries nurseries based on Thalassia ecosystems have been heavily damaged and now lie barren. Man's impact on the estuary where seed restoration was attempted includes the following activities: 50% of the bay bottom directly dredged or filled (leaving much unconsolidated sediment); 50 million gallons of domestic waste dumped directly into a low flushing part of the bay for 20 years; seven major causeways transecting the bay, restricting circulation and flushing; two artificial inlets made into navigational channels; freshwater sheet flow drastically changed due to channelization by flood-control canals; urban runoff from a million people entering the bay. Most of the impacts have now abated; however, their long-term effects remain.

Thorhaug, A.

1980-03-01

277

Research, Monitoring, and Evaluation for the Federal Columbia River Estuary Program  

SciTech Connect

The purpose ofthis document is to describe research, monitoring, and evaluation (RME) for the Federal Columbia River Estuary Program. The intent of this RME effort is to provide data and information to evaluate progress toward meeting program goals and objectives and support decision-making in the Estuary Program. The goal of the Estuary Program is to understand, conserve, and restore the estuary ecosystem to improve the performance of listed salmonid populations. The Estuary Program has five general objectives, designed to fulfill the program goal, as follows. 1. Understand the primary stressors affecting ecosystem controlling factors, such as ocean conditions and invasive species. 2. Conserve and restore factors controlling ecosystem structures and processes, such as hydrodynamics and water quality. 3. Increase the quantity and quality of ecosystem structures, i.e., habitats, juvenile salmonids use during migration through the estuary. 4. Maintain the food web to benefit salmonid performance. 5. Improve salmonid performance in terms of life history diversity, foraging success, growth, and survival. The goal of estuary RME is to provide pertinent and timely research and monitoring information to planners, implementers, and managers of the Estuary Program. In conclusion, the estuary RME effort is designed to meet the research and monitoring needs of the estuary Program using an adaptive management process. Estuary RME's success and usefulness will depend on the actual conduct of adaptive management, as embodied in the objectives, implrementation, data, reporting, and synthesis, evaluation, and decision-making described herein.

Johnson, Gary E.; Diefenderfer, Heida L.; Ebberts, Blaine D.; Tortorici, Cathy; Yerxa, Tracey; Leary, J.; Skalski, John R.

2008-02-05

278

The chemical oceanographic consequences of environmental restoration projects in the Golden Horn estuary (Marmara Sea, Turkey).  

PubMed

The input of industrial and domestic waste to the horizontal circulation in the Golden Horn Estuary of Marmara Sea has resulted in one of the most polluted estuaries in the past. Consequently, the dissolved oxygen concentrations in both the surface and bottom waters decreased toward to the estuary head during 1998-2005. In contrast, the total suspended solids content of the surface water decreased toward to the estuary mouth. However, construction of the operational collector system surrounding the estuary during the process of rehabilitation projects, combined with the opening of the middle pontoons of the Valide Sultan Bridge, resulted in gradually improved water quality of the estuary with a concomitant decrease in pollution. However, phytoplankton blooms and eutrophication persist especially in the innermost part of the Golden Horn in 2005. The region from the estuary mouth up to Camialti has a dynamic structure, and sufficient circulation seemingly occurs in this part of the Golden Horn. PMID:19353286

Balkis, N; Müftüo?lu, E; Aksu, A; Sur, H I; Apak, R

2010-05-01

279

Crumb rubber feasibility report  

SciTech Connect

The Cumberland County supply region generates approximately 58,000 tons of scrap tires each year, equivalent to 45,000 tons of rubber after processing. Approximately 8,000 tons per year are in concentrated locations and can be easily collected. The costs of collection for the remainder vary significantly. Given current markets, economically feasible processes (ambient technology) can reprocess approximately 65 to 75 percent of the 37,000 tons into a marketable product. A processing plant sized for this supply would process 120 tons per day, a viable plant by industry standards. The end uses for whole tires constitute a negligible market, aside from the retreader market. Crumbed rubber is the major development efforts, there are potentially large opportunities in North Carolina.

NONE

1985-11-01

280

ENGINEERING TECHNOLOGY Engineering Technology  

E-print Network

ENGINEERING TECHNOLOGY Engineering Technology Program The Bachelor of Science in Engineering Technology (BSET) is a hands-on program based upon engineering technology fundamentals, engineering for employment or further education. The focus is on current engineering technology issues and applications used

281

Feasibility of Starting a Waterjet Fabrication Plant in Amman, Jordan  

E-print Network

Engineering Management Field Project Feasibility of Starting a Waterjet Fabrication Plant in Amman, Jordan By Khaled A. Ahmad Spring Semester, 2010 An EMGT Field Project report submitted to the Engineering Management... and library search support. 3 Preface It has been my desire for a long time to investigate what it takes to start a water jet fabrication plant in Amman, Jordan to precisely cut marble, granite, and ceramics. I worked in the manufacturing...

Ahmad, Khaled A.

2010-05-14

282

ASSESSING THE ECOLOGICAL CONDITION OF VERACRUZ, MX ESTUARIES  

EPA Science Inventory

As part of an international technology transfer activity between EPA's Office of Research and Development and the state of Veracruz's Sub-secretary of the Environment, 50 stations within estuaries along the gulf coast of the state of Veracruz MX, were sampled during June and July...

283

ASSESSING THE ECOLOGICAL CONDITION OF VERACRUZ, MEXICO ESTUARIES  

EPA Science Inventory

Macauley, John, Hector A. Vasquez, George Craven and P. Thomas Heitmuller. In press. Assessing the Ecological Condition of Veracruz, Mexico Estuaries (Abstract). To be presented at the EPA Science Forum: Healthy Communities and Ecosystems, 1-3 June 2004, Washington, DC. 1 p. (ERL...

284

Stream, lake, estuary, and ocean pollution, 2nd edition  

Microsoft Academic Search

This book, an updated version of the 1985 edition, contains thirteen chapters, beginning with a preface which provides the objective of the book. The primary objective is to offer a comprehensive survey of the biological, hydrological, mathematical, and biochemical aspects of stream, lake, estuary, and ocean pollution analysis. The book also contains ten appendices of useful tables and nomographs of

Nemerow

1991-01-01

285

Production studies in the Mackenzie River — Beaufort Sea estuary  

Microsoft Academic Search

Production studies were carried out in the Mackenzie River\\/Beaufort Sea estuary during the summer of 1986. Results indicate that there were two plankton communities. One was located near the river mouth and was characterized by high dissolved organic carbon, high bacterial activity and a community of amphipods. The second community was associated with high phytoplankton production off shore and with

T. R. Parsons; D. G. Webb; H. Dovey; R. Haigh; M. Lawrence; G. E. Hopky

1988-01-01

286

Sources and Loading of Nitrogen to U.S. Estuaries  

EPA Science Inventory

Previous assessments of land-based nitrogen loading and sources to U.S. estuaries have been limited to estimates for larger systems with watersheds at the scale of 8-digit HUCs and larger, in part due to the coarse resolution of available data, including estuarine watershed bound...

287

Acoustic sensor coverage variation due to water stratification in estuaries  

Microsoft Academic Search

Monitoring underwater environments is critical for future near-shore exploration and port security. The effectiveness of underwater acoustic sensor systems is affected by the water environment, as sharp gradients in salinity and temperature cause sound to refract and reflect. Sound transmission can be impaired in estuaries where the salinity of the water is highly variable in space, and tidal action causes

Hongyuan Shi; Dov Kruger

2009-01-01

288

BENTHIC NUTRIENT FLUX IN A SMALL ESTUARY IN NORTHWESTERNFLORIDA (USA)  

EPA Science Inventory

Benthic Nutrient Flux in a Small Estuary in Northwestern Florida(USA).Gulf and Caribbean Research 18, 15-25, 2006. Benthic nutrient fluxes of ammonium (NH4+), nitrite/nitrate (NO2-+NO3-), phosphate (PO4-), and dissolved silica (DSi) were measured in Escambia Bay, an estuar...

289

The tidal asymmetries and residual flows in Ems Estuary  

NASA Astrophysics Data System (ADS)

A 3D unstructured-grid numerical model of the Ems Estuary is presented. The simulated hydrodynamics are compared against tidal gauge data and observations from research cruises. A comparison with an idealized test reveals the capability of the model to reproduce the secondary circulation patterns known from theoretical results. The simulations prove to be accurate and realistic, confirming and extending findings from earlier observations and modeling studies. The basic characteristics of dominant physical processes in the estuary such as tidal amplification, tidal damping, overtide generation, baroclinicity and internal mixing asymmetry are quantified. The model demonstrates an overall dominance of the flood currents in most of the studied area. However, the hypsometric control in the vicinity of Dollart Bay reverses this asymmetry, with the ebb currents stronger than the flood ones. Small-scale bathymetric characteristics and baroclinicity result in a very complex interplay between dominant physical mechanisms in different parts of the tidal channels and over the tidal flats. Residual flow reveals a clear overturning circulation in some parts of the estuary which is related to a mixing asymmetry between flood and ebb currents. We demonstrate that while areas close to the tidal river exhibit overall similarity with density controlled estuarine conditions, in large areas of the outer estuary barotropic forcing and complex bathymetry together with the density distribution affect substantially the horizontal circulation.

Pein, Johannes Ulrich; Stanev, Emil Vassilev; Zhang, Yinglong Joseph

2014-10-01

290

AFS Estuaries Section Newsletter Newsletter Editor Lee Benaka  

E-print Network

activity I'm looking forward to is the annual AFS meeting in Quebec City on August 17 � 21. Our annual at QUEBEC CITY FEATURE ARTICLE The Health of Juvenile Fishes in Virginia Estuaries WHAT'S GOING, healthy and productive summer, and I look forward to seeing many of you in Quebec City. --Abigail Franklin

291

Variations of the sea level in the Amazon Estuary  

Microsoft Academic Search

We analyze the Geosat altimeter data off the mouth of the Amazon river. Variations of the sea level of up to 6 m are observed, which are correlated with bathymetry, and dominated by a complex tidal pattern. M2, N2 and O1 altimetric cotidal maps are constructed. Their amplitudes decrease strongly off the river mouth, probably by dissipation in the estuary.

J.-F. Minster; M.-L. Genco; C. Brossier

1995-01-01

292

Willamette and Estuary, Lower Columbia Habitat Site Visits & Presentations  

E-print Network

, Ann Creason) Three-day Overview Vans/Drivers: Erik Merrill (503-250-0632) and Lynn Palensky (cell: 503;Presentation Schedule: Estuary, Lower Col, and Willamette March 19th 8:30-11:30 TIME Project # Title Sponsor 8 Lake property to observe re-vegetation work, channel reconnection. Depart Harkens Lake for Portland

293

STATISTICAL SUMMARY EMAP-ESTUARIES VIRGINIAN PROVINCE - 1991  

EPA Science Inventory

Annual monitoring of indicators of the ecological condition of bays and estuaries within the Virginian Province (Cape Cod, MA to Cape Henry, VA) was conducted by the U.S. EPA's Environmental Monitoring and Assessment Program (EMAP) during July, August, and September, 1991. ata we...

294

ROBINSON ESTUARY PRESERVE COASTAL WETLAND HABITAT RESTORATION MX964231  

EPA Science Inventory

This project will create/enhance approximately 397 acres of habitat in the Robinson Estuary Preserve through wetland creation, transitional and coastal upland enhancement, and exotics control. Section 104(b)(3) of the Clean Water Act will be supported by the proposed project thro...

295

Phytoplankton Ecology of North Carolina Estuaries Michael A. Mallin  

E-print Network

interaction between meteorology and hydrology, resulting in periodic winter or early spring algal blooms coastal plain rivers were often subject to summer blue-green algal blooms. Formation of these blooms estuaries and stimulate the blooms, whereas dry winters resulted in low winter phytoplankton abundance

Mallin, Michael

296

Haplosporidian Diseases of Imported Oysters, Ostrea edulis, in Dutch Estuaries  

E-print Network

Haplosporidian Diseases of Imported Oysters, Ostrea edulis, in Dutch Estuaries PAUL van BANNING and growing of mussels, Mytilus edulis, and oysters. Concerning the lat- ter, it can be stated that apart from some small samples of Japanese oyster, Crassostrea gigas, and the Portuguese oyster, Crassostrea

297

SUSCEPTIBILITY OF A NORTHEASTERN GULF OF MEXICO ESTUARY TO HYPOXIA  

EPA Science Inventory

Bottom water hypoxia is a common adverse consequence of nutrient enrichment in estuaries and coastal waters. To protect against hypoxia, it is helpful to know which waters are most susceptible to hypoxia. Hypoxia has been observed regularly in Pensacola Bay, a northeastern Gulf o...

298

SAN JUAN BAY ESTUARY, COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN  

EPA Science Inventory

This Comprehensive Conservation and Management Plan (CCMP) contains information about the overall health of the San Juan Bay Estuary (SJBE) as well as proposed solutions to identified problems. These solutions, or Action Plans, are the result of a more than 4-year process of cons...

299

LATITUDINAL GRADIENTS IN BENTHIC COMMUNITY COMPOSITION IN WESTERN ATLANTIC ESTUARIES  

EPA Science Inventory

The community structure of benthic macroinvertebrates from estuaries along the Atlantic coast of North America from Cape Cod, MA, to Biscayne Bay, FL, were compared. Benthic data were collected over a 5 year period (1990 to 1995) by the U.S. Environmental Protection Agency's Envi...

300

Estuarine habitat utilization by birds in Yaquina Estuary, Oregon  

EPA Science Inventory

A wide variety of bird species are highly dependent on intertidal wetland habitats. Because of this dependency, birds are viewed as important indicators of wetland structure and function. Wetlands in Yaquina Bay along with the tidal wetlands in other Pacific coastal estuaries r...

301

Approaches for Development of Nutrient Criteria in Oregon Estuaries  

EPA Science Inventory

Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

302

Polycyclic aromatic hydrocarbons in San Francisco Estuary sediments  

E-print Network

. The estuary receives stormwater and wastewater effluents from 40 municipal wastewater treatment plants, 30 manufactured goods and raw materials. In addition, the Bay Area was recently cited as having the second highest of the U.S. and the primary receiving water body of the Bay Area. Freshwater flows in primarily through

303

Forward for book entitled "Estuaries: Classification, Ecology, and Human Impacts"  

EPA Science Inventory

The author was introduced to the science of estuaries as a graduate student in the early 1980s, studying the ecology of oyster populations in Chesapeake Bay. To undertake this research, he needed to learn not only about oyster biology, but also about the unique physical and chemi...

304

Geochemical processes in the Yenisei River and Estuary  

Microsoft Academic Search

As a part of the Russian-German project “Siberian River-Runoff (SIRRO)” the major element composition of the dissolved load and the major and trace element composition of particulate load and bottom sediment of the Yenisei River and Estuary were analyzed and examined in context of the basin lithology and climate> In addition, the processes controlling the transformation of the river load

B. Beeskow; V. Rachold

2003-01-01

305

Mercury bioaccumulation in organisms from three Puerto Rican estuaries  

Microsoft Academic Search

We analyzed mercury levels in shrimp (Palaemonetes sp.), Blue Crabs (Callinectes sp.), fish (Tarpon Megalops atlantica and Tilapia Tilapia mossambica), lizards (Ameiva exsul), Cattle Egret (Bubulcus ibis) and Moorhen (Gallinula chloropus) in three estuaries in Puerto Rico in 1988. There were no quantifiable concentrations greater than the method detection limit of mercury in shrimp, crabs and lizards from any site.

Joanna Burger; Keith Cooper; Jorge Saliva; D. Gochfeld; D. Lipsky; Michael Gochfeld

1992-01-01

306

BIVALVES AS BIOMONITORS IN THE NEUSE RIVER AND ESTUARY  

EPA Science Inventory

In eastern North Carolina the Neuse River and Neuse Estuary have been heavily impacted by the byproducts of row crop and livestock agriculture, forestry operations, and industry as well as effluent from municipal wastewater treatment plants. Non-point pollutants derived from thes...

307

PEAK STREAMFLOW - VIRGINIA PORTION OF THE ALBEMARLE-PAMLICO ESTUARY  

EPA Science Inventory

Peak discharge data from the U.S. Geological Survey (http://waterdata.usgs.gov/nwis-w/VA) for gaging stations within the Virginia portion of the Albemarle-Pamlico Estuary watershed. Record dates vary by gaging station. Data for each station are located in a text file named by sta...

308

DAILY STREAMFLOW - VIRGINIA PORTION OF THE ALBEMARLE-PAMLICO ESTUARY  

EPA Science Inventory

Daily mean discharge data from the U.S. Geological Survey (http://waterdata.usgs.gov/nwis-w/VA) for gaging stations within the Virginia portion of the Albemarle-Pamlico Estuary watershed. Record dates vary by gaging station. Data for each station are located in a text file named ...

309

Biological Uptake of Dissolved Silica in the Amazon River Estuary  

Microsoft Academic Search

Approximately 25 percent of the dissolved silica carried by the Amazon River is depleted through diatom production in the inner estuary. Annual production of opaline frustules is estimated to be 15 million tons. However, few diatoms accumulate in modern shelf sediments and chemical recycling appears to be slight. Instead, many frustules apparently are transported landward into the river system, where

John D. Milliman; Edward Boyle

1975-01-01

310

Dissolved Oxygen Saturation Controls PAH Biodegradation in Freshwater Estuary Sediments  

Microsoft Academic Search

Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in terrestrial and aquatic environments and can represent a significant constituent of the carbon pool in coastal sediments. We report here the results of an 18-month seasonal study of PAH biodegradation and heterotrophic bacterial production and their controlling biogeochemical factors from 186 sediment samples taken in a tidally influenced freshwater estuary. For each

T. J. Boyd; M. T. Montgomery; J. K. Steele; J. W. Pohlman; S. R. Reatherford; B. J. Spargo; D. C. Smith

2005-01-01

311

Sedimentologic history of the Loxahatchee River estuary, Florida  

SciTech Connect

Short-term and long-term history of sedimentation in the Loxahatchee River estuary was evaluated based on field sampling and observations, as well as on laboratory analyses of core borings taken through the Holocene sedimentary sequences within the estuary basin. In the main body of the estuary away from sandbars, the sedimentary sequences were dominated by bioturbated mud, or mottled muddy sand, to depths of about 30 centimeters below the sediment surface and by interlayered sand and mud with high-organic content below the bioturbated zone. The biological reworking of the near-surface sediment is interpreted as the result of increased marine influences, possibly associated with ''permanently'' opening and maintaining Jupiter Inlet since the late 1940's and with altered freshwater runoff. Sedimentation rates based on radiocarbon dates have decreased from 0.69 millimeter per year about 7000 years ago to about 0.25 millimeter per year 1000 years ago. Although this trend is associated with a decrease in the rate at which sea level has been rising, sedimentation rates nevertheless have not kept up with rises in sea level. Other evidence indicates that sediment is being provided to the estuary at much higher rates than it is actually accumulating, and this suggests that dynamic physical processes of circulation and flushing are inhibiting rapid sediment accumulation. 15 refs., 31 figs., 5 tabs.

Wanless, H.; Rossinsky, V. Jr.; McPherson, B.F.

1984-01-01

312

ANIMAL-HABITAT ASSOCIATIONS IN PACIFIC NORTHWEST ESTUARIES  

EPA Science Inventory

The mission of the Pacific Coastal Ecology Branch (EPA, Newport, OR) is to determine the effects of habitat alteration by stressors on ecological resources in Pacific Northwest (PNW) estuaries. Research being conducted in support of this mission includes identifying critical hab...

313

The Estuary of the Hudson River, U.S.A  

Microsoft Academic Search

The Hudson River is a major waterway of the eastern seaboard of the United States. Its two major tributaries, the Mohawk and Hudson, combine to form the long narrow estuary of the Lower Hudson. The area is populous and industrially developed, and it is predicted that both domestic and industrial demands for water will increase, as well as the demand

Gwyneth P. Howells

1972-01-01

314

Man's Impact on the Environment: The Estuary as an Ecosystem.  

ERIC Educational Resources Information Center

This environmental education guide focuses on man's impact on the estuary. The program contained in the guide is developed around the following nine questions: (1) What is a definition of the ecosystem being investigated?; (2) What are some of the biotic and abiotic features of the ecosystem and how do these features interrelate?; (3) Where are…

Brevard County School Board, Cocoa, FL.

315

Metals in the sediments along the Hudson River estuary  

Microsoft Academic Search

The distribution of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in bottom and suspended sediments from the ocean up the Hudson River estuary for 70 km were analyzed. The bottom sediments has a metal concentration maximum in the harbor. Everywhere studied, the metal concentrations in suspension are much higher than in the bottom sediments by 30

R Gibbs

1994-01-01

316

Decadal to Millennial Sedimentation Patterns of the Hudson River Estuary  

Microsoft Academic Search

The Hudson River Estuary (HRE) is adjacent to large metropolitan areas including New York City. Understanding the variable energy conditions for transporting sediments is key to deal with environmental pollution such as the controversial burial and dredging of PCB's in the HRE. We studied sediment transport in the HRE by examining more than 150 cores and grab samples interpreted within

M. Jones; C. M. McHugh; L. Burckle; S. Pekar; G. Pereira; W. B. Ryan; R. Bell; S. Carbotte

2002-01-01

317

7 CFR 1980.442 - Feasibility studies.  

...Technical feasibility. Technical feasibility reports shall be prepared by...the application. The technical feasibility reports shall address the suitability...For the purpose of the technical feasibility reports, the project...

2014-01-01

318

Biogeochemical value of managed realignment, Humber estuary, UK.  

PubMed

We outline a plausible, albeit extreme, managed realignment scenario ('Extended Deep Green' scenario) for a large UK estuary to demonstrate the maximum possible biogeochemical effects and economic outcomes of estuarine management decisions. Our interdisciplinary approach aims to better inform the policy process, by combining biogeochemical and socioeconomic components of managed realignment schemes. Adding 7494 ha of new intertidal area to the UK Humber estuary through managed realignment leads to the annual accumulation of a 1.2 x 10(5) t of 'new' sediment and increases the current annual sink of organic C and N, and particle reactive P in the estuary by 150%, 83% and 50%, respectively. The increase in intertidal area should also increase denitrification. However, this positive outcome is offset by the negative effect of enhanced greenhouse gas emissions in new marshes in the low salinity region of the estuary. Short-term microbial reactions decrease the potential benefits of CO(2) sequestration through gross organic carbon burial by at least 50%. Net carbon storage is thus most effective where oxidation and denitrification reactions are reduced. In the Humber this translates to wet, saline marshes at the seaward end of estuaries. Cost-benefit analysis (CBA) was used to determine the economic efficiency of the Extended Deep Green managed realignment. When compared to a 'Hold-the-Line' future scenario, i.e. the present state/extent of sea defences in the estuary, the CBA shows that managed realignment is cost effective when viewed on >25 year timescales. This is because capital costs are incurred in the first years, whereas the benefits from habitat creation, carbon sequestration and reduced maintenance costs build up over time. Over 50- and 100-year timescales, the Extended Deep Green managed realignment scenario is superior in efficiency terms. The increased sediment accumulation is also likely to enhance storage of contaminant metals. In the case of Cu, a metal that currently causes significant water quality issues, Cu removal due to burial of suspended sediment in realigned areas translates to a value of approximately pounds sterling 1000 a(-1) (avoided clean up costs). Although this is not formally included in the CBA it illustrates another likely positive economic outcome of managed realignment. Although we focus on the Humber, the history of reclamation and its biogeochemistry is common to many estuaries in northern Europe. PMID:16996577

Andrews, J E; Burgess, D; Cave, R R; Coombes, E G; Jickells, T D; Parkes, D J; Turner, R K

2006-12-01

319

Tribal Utility Feasibility Study  

SciTech Connect

The Schatz Energy Research Center (SERC) assisted the Yurok Tribe in investigating the feasibility of creating a permanent energy services program for the Tribe. The original purpose of the DOE grant that funded this project was to determine the feasibility of creating a full-blown Yurok Tribal electric utility to buy and sell electric power and own and maintain all electric power infrastructure on the Reservation. The original project consultant found this opportunity to be infeasible for the Tribe. When SERC took over as project consultant, we took a different approach. We explored opportunities for the Tribe to develop its own renewable energy resources for use on the Reservation and/or off-Reservation sales as a means of generating revenue for the Tribe. We also looked at ways the Tribe can provide energy services to its members and how to fund such efforts. We identified opportunities for the development of renewable energy resources and energy services on the Yurok Reservation that fall into five basic categories: • Demand-side management – This refers to efforts to reduce energy use through energy efficiency and conservation measures. • Off-grid, facility and household scale renewable energy systems – These systems can provide electricity to individual homes and Tribal facilities in areas of the Reservation that do not currently have access to the electric utility grid. • Village scale, micro-grid renewable energy systems - These are larger scale systems that can provide electricity to interconnected groups of homes and Tribal facilities in areas of the Reservation that do not have access to the conventional electric grid. This will require the development of miniature electric grids to serve these interconnected facilities. • Medium to large scale renewable energy development for sale to the grid – In areas where viable renewable energy resources exist and there is access to the conventional electric utility grid, these resources can be developed and sold to the wholesale electricity market. • Facility scale, net metered renewable energy systems – These are renewable energy systems that provide power to individual households or facilities that are connected to conventional electric utility grid.

Engel, R. A.; Zoellick, J. J.

2007-06-30

320

Feasibility Study on Solid Waste to Energy Technological Aspects  

E-print Network

Feasibility Study on Solid Waste to Energy Technological Aspects Yuzhong Tan College of Engineering://www.funginstitute.berkeley.edu/sites/default/ les/SolidWasteToEnergy.pdf April 15, 2013 130 Blum Hall #5580 Berkeley, CA 94720-5580 | (510) 664 seeks to compare and evaluate each technology by reviewing waste to energy reports and seeking

Sekhon, Jasjeet S.

321

Waste-To-Energy Feasibility Analysis: A Simulation Model  

E-print Network

Waste- To- Energy Feasibility Analysis: A Simulation Model Viet- An Duong College of Engineering://www.funginstitute.berkeley.edu/sites/default/ les/WasteToEnergy.pdf May 1, 2014 130 Blum Hall #5580 Berkeley, CA 94720-5580 | (510) 664-4337 | www in renewable energies, with very low CO2 emis- sions, making waste- to- energy a clean source of energy

Sekhon, Jasjeet S.

322

The MRIS feasibility study  

NASA Technical Reports Server (NTRS)

The Microwave Reflectometer Ionization Sensor (MRIS) is an instrument being developed for use in detecting and ranging of electron density layers in the reentry plasma of a space transfer vehicle. The rationale for the selection of the Double Sideband Suppressed Carrier (DSBSC) system used in the feasibility study for the MRIS is presented. A 25 GHz single-oscillator system and a 220 GHz double-oscillator system are described. The 25 GHz system was constructed and tested in the laboratory and test results are presented. As developed, the system employs a sideband spacing of 160 MHz. Based on an estimated electromagnetic wave velocity in the plasma, a round-trip phase shift measurement accuracy of +/- 7.6 degrees was required for the desired +/- 1/2 cm distance measurement accuracy. The interaction of parallel ground and reflecting planes produces interference that prevents the basic DSBSC system from meeting the accuracy goal so a frequency modulation was added to the system to allow averaging of the measured phase deviation. With an FM deviation of +/- 1 GHz, laboratory measurements were made for distances from 5 to 61 cm tip free space. Accounting for the plasma velocity factor, 82 percent of the data were equal to or better than the desired accuracy. Based on this measured result a sideband spacing to 250 MHz could be expected to yield data approximately 96 percent within the accuracy goal.

Neece, Robert T.; Cross, Aubrey E.; Schrader, James H.

1993-01-01

323

Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, Annual Report 2009  

SciTech Connect

This report describes the 2009 research conducted under the U.S. Army Corps of Engineers (USACE or Corps) project EST-09-P-01, titled “Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary.” The research was conducted by the Pacific Northwest National Laboratory, Marine Science Laboratory and Hydrology Group, in partnership with the University of Washington, School of Aquatic and Fishery Sciences, Columbia Basin Research, and Earl Dawley (NOAA Fisheries, retired). This Columbia River Fish Mitigation Program project, referred to as “Salmonid Benefits,” was started in FY 2009 to evaluate the state-of-the science regarding the ability to quantify the benefits to listed salmonids1 of habitat restoration actions in the lower Columbia River and estuary.

Diefenderfer, Heida L.; Johnson, Gary E.; Sather, Nichole K.; Skalski, John R.; Dawley, Earl M.; Coleman, Andre M.

2010-08-01

324

Residual fluxes of suspended sediment in a tidally dominated tropical estuary  

NASA Astrophysics Data System (ADS)

This paper assesses the fine sediment fluxes in the Caravelas estuarine system (Bahia, Brazil, 17o45'S and 039o12'W). The estuary reaches the ocean at the shore across from the Abrolhos Bank, the largest tropical reef habitat in the South Atlantic. The Caravelas estuarine system is composed of several meandering channels, which are connected to the ocean by a double inlet system. These two openings - the Caravelas and Nova Viçosa estuaries - are connected by a narrow, 30 km long channel. The Caravelas estuary does not receive significant continental input, while the Nova Viçosa estuary receives the contribution of the Peruíbe River, which drains an area of approximately 5000 km2. To understand the fine sediment dynamics and net transport, observations of tides, currents, salinity and suspended sediment concentration (SSC) were recorded in 13-h tidal surveys (spring and neap tide) and with 20-day long CTDs/ADCP moorings at the Caravelas estuary and in the interconnection channel. The SSC dynamic in the Caravelas estuary is primarily driven by advection, with SSC originating in the inlet and inner shelf area. Residual water and sediment transport are up-estuary in the Caravelas estuary and toward the Caravelas estuary in the interconnection channel. The residual transport showed pronounced synodical modulation and was stronger during spring tide. The Caravelas estuary function as a trap for inner shelf materials and fine sediments delivered by the Peruípe River at Nova Viçosa.

Schettini, Carlos Augusto França; Duarte Pereira, Marçal; Siegle, Eduardo; de Miranda, Luiz Bruner; Silva, Mário P.

2013-11-01

325

Response of the turbidity maximum zone to fluctuations in sediment discharge from river to estuary in the Changjiang Estuary (China)  

NASA Astrophysics Data System (ADS)

In the Changjiang Estuary, interactions between the sea and the river result in the development of a turbidity maximum zone (TMZ). Riverine sediments are an important source for TMZ formation. Since the 1960s, sediment discharge from the river basin to the estuary has decreased due to dam construction, water and soil conservation, and water diversion projects. Thirty-two Landsat images of the estuary, covering the period from 1979 to 2008, were collected to identify the TMZ response to sediment decline. A threshold value of suspended sediment concentration (SSC) of 0.7 kg/m3, corresponding to a spectrum reflectance of 5% of Landsat MSS band 7 and 7% of Landsat TM/ETM band 4, was used to identify the Changjiang Estuary TMZ. The TMZ area was then extracted from each image to investigate its temporal and spatial variations during the past 30 years. The images were grouped into five time series; the average TMZ area of each series was estimated. The results show that the TMZ area declined 23% from series (a) to series (e), responding to a 77% reduction in riverine sediment discharge. In addition, the TMZ had strong seasonal and tidal variations; it was generally larger during flood seasons than during dry seasons and during spring tides compared to neap tides. The spring/neap tidal cycle played a more important role in TMZ change than did the seasonal cycle. Due to the continued reduction of sediment discharge to the estuary resulting from dams already constructed and to those that will be constructed upstream in the Changjiang River, it is predicted that the TMZ area will continue decreasing and that the re-suspension of local sediments will play a more important role in the formation of the TMZ.

Jiang, Xuezhong; Lu, Bing; He, Yuhong

2013-10-01

326

The Feasibility of Sustainability Reporting  

E-print Network

and Safety, Dartmouth College Beth DiFrancesco, Dartmouth Dining Services, Dartmouth College. Julie DolanThe Feasibility of Sustainability Reporting At Dartmouth College A report by the members of Environmental Studies 50 Spring 2003 #12;#12;The Feasibility of Sustainability Reporting at Dartmouth College

327

Research, Monitoring, and Evaluation for the Federal Columbia River Estuary Program.  

SciTech Connect

The purpose of this document is to describe research, monitoring, and evaluation (RME) for the Federal Columbia River Estuary Program, hereafter called 'the Estuary Program'. The intent of this RME effort is to provide data and information to evaluate progress toward meeting program goals and objectives and support decision making in the Estuary Program. The goal of the Estuary Program is to understand, conserve, and restore the estuary ecosystem to improve the performance of listed salmonid populations. The Estuary Program has five general objectives, designed to fulfill the program goal, as follows: (1) Understand the primary stressors affecting ecosystem controlling factors, such as ocean conditions and invasive species. (2) Conserve and restore factors controlling ecosystem structures and processes, such as hydrodynamics and water quality. (3) Increase the quantity and quality of ecosystem structures, i.e., habitats, juvenile salmonids use during migration through the estuary. (4) Maintain the food web to benefit salmonid performance. (5) Improve salmonid performance in terms of life history diversity, foraging success, growth, and survival. The goal of estuary RME is to provide pertinent and timely research and monitoring information to planners, implementers, and managers of the Estuary Program. The goal leads to three primary management questions pertaining to the main focus of the Estuary Program: estuary habitat conservation and restoration. (1) Are the estuary habitat actions achieving the expected biological and environmental performance targets? (2) Are the offsite habitat actions in the estuary improving juvenile salmonid performance and which actions are most effective at addressing the limiting factors preventing achievement of habitat, fish, or wildlife performance objectives? (3) What are the limiting factors or threats in the estuary/ocean preventing the achievement of desired habitat or fish performance objectives? Performance measures for the estuary are monitored indicators that reflect the status of habitat conditions and fish performance, e.g., habitat connectivity, survival, and life history diversity. Performance measures also pertain to implementation and compliance. Such measures are part of the monitoring, research, and action plans in this estuary RME document. Performance targets specific to the estuary were not included in the 2007 draft Biological Opinion.

Johnson, Gary E.; Diefenderfer, Heida L. (Pacific Northwest National Laboratory)

2008-02-20

328

Suspended Sediment Transport Dynamics in the Sub-tropical Micro-tidal Richmond River Estuary, Australia  

NASA Astrophysics Data System (ADS)

Suspended sediment transport and sedimentation dynamics in the sub-tropical Richmond River estuary were investigated between July 1994 and June 1996. During low flow months the estuary received net sediment inputs from the continental shelf; during high flow the estuary exported sediment to the continental shelf depending on the magnitude of floods. Flow-weighted sampling along with a one-dimensional unsteady flow hydrodynamic model of the estuary estimated that about fifty percent of the flood-borne suspended sediment was transported through the estuary to the continental shelf during two minor floods (with a 2-year return period), whereas, one hundred percent of the flood-borne sediment was transported to the continental shelf during a moderate flood (with a 5-year return period). Marker horizons confirmed a net accumulation of sediment in the Richmond River estuary at the salt-fresh water interface during all post flood recovery stages.

Hossain, S.; Eyre, B.; Mcconchie, D.

2001-05-01

329

Freeport Harbor, Texas, Channel Improvement Project Feasibility Report and Environmental Impact Statement  

E-print Network

) and Environmental Impact Statement (EIS). The Battelle IEPR panel reviewed the Draft Feasibility Report (DFR Impact Statement U.S. Army Corps of Engineers Response to Independent External Peer Review October 2012#12;1 Freeport Harbor, Texas, Channel Improvement Project Feasibility Report and Environmental

US Army Corps of Engineers

330

Multnomah County Hydrokinetic Feasibility Study: Final Feasibility Study Report  

SciTech Connect

HDR has completed a study of the technical, regulatory, and economic feasibility of installing hydrokinetic turbines under the Morrison, Broadway, and Sellwood bridges. The primary objective of installing hydrokinetic turbines is a demonstration of in-stream hydrokinetic technologies for public education and outreach. Due to the low gradient of the Lower Willamette and the effects of the tide, velocities in the area in consideration are simply not high enough to economically support a commercial installation. While the velocities in the river may at times provide enough energy for a commercial turbine to reach capacity, the frequency and duration of high flow events which provide suitable velocities is not sufficient to support a commercial hydrokinetic installation. We have observed that over an 11 year period, daily average velocities in the Lower Willamette exceeded a nominal cut-in speed of 0.75 m/s only 20% of the time, leaving net zero power production for the remaining 80% of days. The Sellwood Bridge site was estimated to have the best hydrokinetic resource, with an estimated average annual production of about 9,000 kWh. The estimated production could range from 2,500 kWh to 15,000 kWh. Based on these energy estimates, the amount of revenue generated through either a power purchase agreement (PPA) or recovered through net metering is not sufficient to repay the project costs within the life of the turbine. The hydrokinetic resource at the Morrison and Broadway Bridges is slightly smaller than at the Sellwood Bridge. While the Broadway and Morrison Bridges have existing infrastructure that could be utilized, the project is not expected to generate enough revenue to repay the investment. Despite low velocities and energy production, the sites themselves are favorable for installation of a demonstration or experimental project. With high public interest in renewable energy, the possibility exists to develop a hydrokinetic test site which could provide developers and scientists a location to temporarily deploy and test hydrokinetic devices, and also function as an educational tool for the general public. Bridge piers provide an excellent pre-existing anchor point for hydrokinetic devices, and existing infrastructure at the Morrison and Broadway Bridges may reduce installation costs. Opportunity exists to partner with local universities with engineering and environmental interest in renewable energy. A partnership with Portland State University�¢����s engineering school could provide students with an opportunity to learn about hydrokinetics through senior design projects. Oregon State University and University of Washington, which are partnered through the Northwest National Marine Renewable Energy Center (NNMREC) to study and test hydrokinetic technology, are also relatively local to the site. In addition to providing an opportunity for both public and private entities to learn technically about in-stream kinetics, this approach will encourage grant funding for outreach, education, and product development, while also serving as a positive community relations opportunity for the County and its partners.

Stephen Spain

2012-03-15

331

Sedimentary facies of the tide-dominated paleo-Changjiang (Yangtze) estuary during the last transgression  

Microsoft Academic Search

A large estuary was formed by marine inundation of the paleo-Changjiang (Yangtze) incised valley during the transgression after the Last Glacial Maximum. This paper presents the sedimentary facies and architecture of the estuary fill, based on the analysis of three sediment cores (CM97, JS98, and HQ98) obtained from the present Changjiang delta plain. Estuary fill deposits showing an upward-fining succession

Kazuaki Hori; Yoshiki Saito; Quanhong Zhao; Xinrong Cheng; Pinxian Wang; Yoshio Sato; Congxian Li

2001-01-01

332

THE BATHYMETRY, ENVIRONMENTAL PARAMETERS AND SEDIMENTS OF THE BOT RIVER ESTUARY, S.W. CAPE PROVINCE  

Microsoft Academic Search

The bathymetry of the Bot River estuary, water-level records from 1978 to 1983, wind records for a three-week period in August-September 1984, and investigations into the particle-size distribution, mineralogy and chemical composition of sediments in the estuary are reported and discussed.The Bot River estuary is generally shallow, too shallow for the development of a halocline. The water-levels fluctuate between approximately

J. P. Willis

1985-01-01

333

Abundance, breeding and growth of the crab Scylla serrata in two South African estuaries  

Microsoft Academic Search

Populations of the crab Scylla serrata (Forskal) were studied in two South African estuaries from 1971 until 1974. One estuary was open to the sea, the other was closed by a sandbar. Population density in the closed estuary was estimated by means of mark-release-recapture data from tagged crabs. The population of S. serrata was estimated as 1 crab\\/124m2 and the

B. J. Hill

1975-01-01

334

Suspended Sediment Transport Dynamics in the Sub-tropical Micro-tidal Richmond River Estuary, Australia  

Microsoft Academic Search

Suspended sediment transport and sedimentation dynamics in the sub-tropical Richmond River estuary were investigated between July 1994 and June 1996. During low flow months the estuary received net sediment inputs from the continental shelf; during high flow the estuary exported sediment to the continental shelf depending on the magnitude of floods. Flow-weighted sampling along with a one-dimensional unsteady flow hydrodynamic

S. Hossain; B. Eyre; D. Mcconchie

2001-01-01

335

Estuaries of the Northeastern United States: Habitat and Land Use Signatures  

Microsoft Academic Search

Geographic signatures are physical, chemical, biotic, and human-induced characteristics or processes that help define similar or unique features of estuaries along latitudinal or geographic gradients. Geomorphologically, estu- aries of the northeastern U.S., from the Hudson River estuary and northward along the Gulf of Maine shoreline, are highly diverse because of a complex bedrock geology and glacial history. Back-barrier estuaries and

CHARLES T. R OMAN; NORBERT JAWORSKI; F REDERICK; T. S HORT; S TUART FINDLAY; R. SCOTT WARREN

2000-01-01

336

Turbulence characteristics of a small subtropical estuary during and after some moderate rainfall  

Microsoft Academic Search

In natural estuaries, scalar diffusion and dispersion are driven by turbulence. In the present study, detailed turbulence measurements were conducted in a small subtropical estuary with semi-diurnal tides under neap tide conditions. Three acoustic Doppler velocimeters were installed mid-estuary at fixed locations close together. The units were sampled simultaneously and continuously at relatively high frequency for 50h. The results illustrated

Mark Trevethan; Hubert Chanson; Richard Brown

2008-01-01

337

Rapid Communication: Climatic Control on Eutrophication of the Hudson River Estuary  

Microsoft Academic Search

Eutrophication is arguably the biggest pollution problem facing estuaries globally, with extensive consequences including\\u000a anoxic and hypoxic waters, reduced fishery harvests, toxic algal blooms, and loss of biotic diversity. However, estuaries\\u000a vary greatly in their susceptibility to eutrophication. The Hudson River estuary receives very high levels of nutrient inputs\\u000a yet in the past has shown relatively low rates of phytoplankton

Robert W. Howarth; Dennis P. Swaney; Thomas J. Butler; Roxanne Marino

2000-01-01

338

A Decade of Change in the Skidaway River Estuary. III. Plankton  

Microsoft Academic Search

The Skidaway River estuary, GA (USA), a tidally dominated subtropical system surrounded by extensive Spartina salt marshes, is experiencing steady increases in nutrients, chlorophyll, and particulate matter and decline in dissolved\\u000a oxygen, associated with cultural eutrophication. A long-term study is documenting changes in these parameters: previous papers\\u000a Verity (Estuaries 25:944–960, 2002a, Estuaries 25:961–975, b) reported on hydrography, nutrients, chlorophyll, and

Peter G. Verity; David G. Borkman

2010-01-01

339

Planetary engineering  

NASA Astrophysics Data System (ADS)

Assuming commercial fusion power, heavy lift vehicles and major advances in genetic engineering, the authors survey possible late-21st century methods of working major transformations in planetary environments. Much more Earthlike climates may be produced on Mars by generating low freezing point greenhouse gases from indigenous materials; on Venus by biological conversion of CO2 to graphite, by canceling the greenhouse effect with high-altitude absorbing fine particles, or by a sunshield at the first Lagrangian point; and on Titan by greenhouses and/or fusion warming. However, in our present state of ignorance we cannot guarantee a stable endstate or exclude unanticipated climatic feedbacks or other unintended consequences. Moreover, as the authors illustrate by several examples, many conceivable modes of planetary engineering are so wasteful of scarce solar system resources and so destructive of important scientific information as to raise profound ethical issues, even if they were economically feasible, which they are not. Global warming on Earth may lead to calls for mitigation by planetary engineering, e.g., emplacement and replenishment of anti-greenhouse layers at high altitudes, or sunshields in space. But here especially we must be concerned about precision, stability, and inadvertent side-effects. The safest and most cost-effective means of countering global warming - beyond, e.g., improved energy efficiency, CFC bans and alternative energy sources - is the continuing reforestation of approximately 2 times 107 sq km of the Earth's surface. This can be accomplished with present technology and probably at the least cost.

Pollack, James B.; Sagan, Carl

340

Planetary engineering  

NASA Technical Reports Server (NTRS)

Assuming commercial fusion power, heavy lift vehicles and major advances in genetic engineering, the authors survey possible late-21st century methods of working major transformations in planetary environments. Much more Earthlike climates may be produced on Mars by generating low freezing point greenhouse gases from indigenous materials; on Venus by biological conversion of CO2 to graphite, by canceling the greenhouse effect with high-altitude absorbing fine particles, or by a sunshield at the first Lagrangian point; and on Titan by greenhouses and/or fusion warming. However, in our present state of ignorance we cannot guarantee a stable endstate or exclude unanticipated climatic feedbacks or other unintended consequences. Moreover, as the authors illustrate by several examples, many conceivable modes of planetary engineering are so wasteful of scarce solar system resources and so destructive of important scientific information as to raise profound ethical issues, even if they were economically feasible, which they are not. Global warming on Earth may lead to calls for mitigation by planetary engineering, e.g., emplacement and replenishment of anti-greenhouse layers at high altitudes, or sunshields in space. But here especially we must be concerned about precision, stability, and inadvertent side-effects. The safest and most cost-effective means of countering global warming - beyond, e.g., improved energy efficiency, CFC bans and alternative energy sources - is the continuing reforestation of approximately 2 times 107 sq km of the Earth's surface. This can be accomplished with present technology and probably at the least cost.

Pollack, James B.; Sagan, Carl

1991-01-01

341

Multibiomarker assessment of three Brazilian estuaries using oysters as bioindicators  

SciTech Connect

Oysters have been largely employed as bioindicators of environmental quality in biomonitoring studies. Crassostrea rhizophorae was selected to evaluate the health status of three estuarine areas impacted by anthropogenic activities along the Brazilian coast, in three estuarine complexes, ranging in latitude from 7 to 25 deg. S. In each estuary three sites were sampled in Winter and in Summer: a site considered as reference, and two sites next to contamination sources. Condition index was similar at all sites and estuaries, with the highest values found for Itamaraca oysters in Summer. Necrosis, hyperplasia, mucocyte hypertrophy and fusion of ordinary filaments were the main histopathological lesions observed. Muscle cholinesterase activity was overall similar, but with a strong seasonal effect. Inhibition or activation of branchial total ATPase and Na,K-ATPase activities at the contaminated sites was observed. The health status of these estuarine areas is quite similar, and the combined use of biomarkers is recommended.

Valdez Domingos, F.X. [Departamento de Biologia Celular, Universidade Federal do Parana. CP. 19031, CEP 81531-990, Curitiba, PR (Brazil)], E-mail: fa_valdez@yahoo.com; Azevedo, M. [Departamento de Fisiologia, Universidade Federal do Parana. CP. 19031, CEP 81531-990, Curitiba, PR (Brazil); Silva, M.D. [Departamento de Farmacologia, Universidade Federal do Parana. CP. 19031, CEP 81531-990, Curitiba, PR (Brazil); Randi, M.A.F. [Departamento de Biologia Celular, Universidade Federal do Parana. CP. 19031, CEP 81531-990, Curitiba, PR (Brazil); Freire, C.A. [Departamento de Fisiologia, Universidade Federal do Parana. CP. 19031, CEP 81531-990, Curitiba, PR (Brazil); Silva de Assis, H.C. [Departamento de Farmacologia, Universidade Federal do Parana. CP. 19031, CEP 81531-990, Curitiba, PR (Brazil); Oliveira Ribeiro, C.A. [Departamento de Biologia Celular, Universidade Federal do Parana. CP. 19031, CEP 81531-990, Curitiba, PR (Brazil)

2007-11-15

342

Contrasting phytoplankton distributions controlled by tidal turbulence in an estuary  

NASA Astrophysics Data System (ADS)

The vertical distribution of three phytoplankton species was monitored over a complete tidal cycle during daylight hours, with specific reference to estuarine hydrodynamics. The data suggest that pelagic diatoms ( Coscinodiscus spp.) and dinoflagellates ( Prorocentrum micans and Peridinium trochoideum) are able to co-exist by utilising contrasting properties of tidal mixing to develop and reside within the partially mixed estuary, Southampton Water, UK. The data imply that the stability within the water column during slack water periods, permits surface aggregation of dinoflagellates which become homogeneously distributed when turbulence intensifies during ebb and flood currents. Diatoms, conversely, rely on the periods of increased turbulent kinetic energy (TKE) to ensure entrainment into the upper water column and to prevent sinking from the photic zone during stable intervals. The unusual tidal regime for this estuary provides a unique environment to investigate the hydrodynamic properties which influence different phytoplankton groups.

Lauria, Mary Lou; Purdie, Duncan A.; Sharples, Jonathan

1999-06-01

343

Mercury bioaccumulation in organisms from three Puerto Rican estuaries.  

PubMed

We analyzed mercury levels in shrimp (Palaemonetes sp.), Blue Crabs (Callinectes sp.), fish (Tarpon Megalops atlantica and Tilapia Tilapia mossambica), lizards (Ameiva exsul), Cattle Egret (Bubulcus ibis) and Moorhen (Gallinula chloropus) in three estuaries in Puerto Rico in 1988. There were no quantifiable concentrations greater than the method detection limit of mercury in shrimp, crabs and lizards from any site. Mercury levels were also below detection limits in Tilapia, except for specimens collected at Frontera Creek, allegedly contaminated with mercury. However, mercury levels ranged from 92-238 ?g/kg (wet weight) in Tarpon, a predaceous fish that feeds on smaller fish. Few of the birds had detectable levels of mercury. Our results indicate relatively low concentrations of mercury in biota collected in all of the three estuaries at most trophic levels, although 10 of 12 Tarpon fillet samples from Frontera had detectable mercury compared to 3 of 12 fillet samples for the other two lagoons. PMID:24226951

Burger, J; Cooper, K; Saliva, J; Gochfeld, D; Lipsky, D; Gochfeld, M

1992-09-01

344

Metals in the sediments along the Hudson River estuary  

SciTech Connect

The distribution of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in bottom and suspended sediments from the ocean up the Hudson River estuary for 70 km were analyzed. The bottom sediments has a metal concentration maximum in the harbor. Everywhere studied, the metal concentrations in suspension are much higher than in the bottom sediments by 30 times for Cd, 20 times for Cu, and 10 to 15 times for Co, Cr, Ni, Pb, and Zn. The composition of metals in the suspended material varied along the estuary with a large metal maximum in the harbor and again in Haverstraw Bay. By standardizing toxic metal concentrations to Fe, a maximum level of pollution in New York Harbor is indicated, along with a lesser maximum in Haverstraw Bay.

Gibbs, R.J. (Univ. of Delaware, Newark, DE (United States))

1994-01-01

345

Contaminant inputs to the Hudson-Raritan estuary  

SciTech Connect

Source locations and an estimate of the magnitude of contaminant inputs to the Hudson-Raritan Estuary are presented. The relative contribution of the various sources is indicated and data gaps are identified. Six sources of contaminant inputs were evaluated: nontidal tributary, municipal and industrial wastewater, atmospheric, urban runoff, accidental spills, and landfill leachate. The latter five sources were evaluated downstream of the tributary water quality stations, since sources above these points are reflected in the tributary inputs. In addition to flow or volume for each source, data on concentrations of conventional pollutants (solids, organic matter, nutrients, and bacterial indicators), organic toxics, and heavy metals were sought. A large quantity of data was obtained from numerous federal, state, county, and municipal agencies, and private firms. The data were analyzed to obtain average mass loads of specific contaminants into the Hudson-Raritan Estuary.

Mueller, J.A.; Gerrish, T.A.; Casey, M.C.

1982-08-01

346

Chlorofluorocarbons in the Hudson estuary during summer months  

SciTech Connect

Chlorofluorocarbon (CFC) concentrations in the Hudson estuary were found to be greater than the atmospheric solubility equilibrium concentration, demonstrating that the entire reach is contaminated with CFCs from local wastewater discharge. Samples have been collected along the axis of the lower Hudson estuary over a 5-month period to assess temporal and spatial variability of their wastewater sources. The highest CFC concentrations were found in water collected near Manhattan. In this region, CFC-11 (CCl{sub 3}F) and CFC-12 (CCl{sub 2}F{sub 2}) were 3 to 5 and 10 to 20 times saturation, respectively. There appears to be a continuous CFC source in the New York City area, although the magnitude of this source declined during summer months. Other large CFC source were found near Albany, and in Haverstraw Bay (60 km north of Manhattan). 29 refs., 6 figs., 3 tabs.

Clark, J.F.; Smethie, W.M. Jr.; Simpson, H.J. [Columbia Univ., Palisades, NY (United States)] [Columbia Univ., Palisades, NY (United States)

1995-10-01

347

Using a Multi-Component Indicator Toward Reducing Phytoplankton Bloom Occurrences in the Swan River Estuary  

NASA Astrophysics Data System (ADS)

The Swan River estuary is an icon of the city of Perth, Western Australia, running through the city centre and dividing the northern from the southern part of the city. However, frequent phytoplankton blooms have been observed in the estuary as a result of eutrophication. The Index of Sustainable Functionality (ISF), a composite index able to indicate for sustainable health of the estuary, was applied, taking into account the hydrology and highly seasonal nature of the estuary to inform the management of the estuary, towards the aim of reducing bloom occurrences. The study period was from the beginning of intensive monitoring in 1995 to mid-2009. The results emphasize the importance of physical controls on the ecology of the estuary. No significant trend in the estuary's low functionality was found, indicating that despite extensive restoration efforts, the frequency of algal bloom occurrences has remained relatively stationary and other mitigating factors have maintained an annual average ISF value at around 70 % functionality. We identified that the low flow season consistently performs the worst, with (high) temperature found as the most dominant variable for phytoplankton growth and bloom. Thus in managing the estuary, vigilance is required during periods of high temperature and low flow. Focusing on the risk of phytoplankton bloom, a nutrient reduction program that is in place is a long term solution due to high concentrations in the estuary. Other management measures need to be considered and adopted to effectively reduce the occurrences of future phytoplankton blooms.

Kristiana, Ria; Antenucci, Jason P.; Imberger, Jorg

2012-08-01

348

WERF MACT Feasibility Study Report  

SciTech Connect

This study was undertaken to determine the technical feasibility of upgrading the Waste Experimental Reduction Facility (WERF) at the Idaho National Engineering and Environmental Laboratory to meet the offgas emission limits proposed in the Maximum Achievable Control Technologies (MACT)rule. Four practicable offgas treatment processes were identified, which, if installed, would enable the WERF to meet the anticipated MACT emission limits for dioxins and furans (D/F), hydrochloric acid (HCI), and mercury (Hg). Due to the three-year time restraint for MACT compliance, any technology chosen for the upgrade must be performed within the general plant project funding limit of $5 M. The option selected consists of a partial-quench evaporative cooler with dry sorbent injection for HCI removal followed by a sulfur-impregnated activated carbon bed for Hg control. The planning cost estimate for implementing the option is $4.17 M (with 24% contingency). The total estimated cost includes capital costs, design and construction costs, and project management costs. Capital costs include the purchase of a new offgas evaporative cooler, a dry sorbent injection system with reagent storage, a new fabric filter baghouse, a fixed carbon bed absorber, and two offgas induced draft exhaust fans. It is estimated that 21 months will be required to complete the recommended modification to the WERF. The partial-quench cooler is designed to rapidly cool the offgas exiting the secondary combustion chamber to minimize D/F formation. Dry sorbent injection of an alkali reagent into the offgas is recommended. The alkali reacts with the HCI to form a salt, which is captured with the fly ash in the baghouse. A design HCI removal efficiency of 97.2% allows for the feeding 20 lbs/hr of chlorine to the WERF incinerator. The sorbent feed rate can be adjusted to achieve the desired HCI removal efficiency. A fixed bed of sulfur-impregnated carbon was conservatively sized for a total Hg removal capacity when feeding 10 g/hr Hg to the WERF incinerator. An added benefit for using carbon adsorption is that the activated carbon will also capture a large fraction of any residual D/F present in the offgas.

B. Bonnema; D. Moser; J. Riedesel; K. Kooda; K. Liekhus; K. Rebish; S. Poling

1998-11-01

349

Engineering. Mechanical Engineering.  

E-print Network

Department Of Mechanical Engineering. Studying Mechanical Engineering. www.sheffield.ac.uk/mecheng #12;from the Head of Department A degree in mechanical engineering is the key to an exciting course is an MEng or BEng in Mechanical Engineering. You can also learn a language and study abroad

Stevenson, Mark

350

Quantitative seasonal aspects of zooplankton in the Delaware River estuary  

Microsoft Academic Search

The Delaware, a major Coastal Plain estuary about 90 miles long, was quantitatively sampled for net zooplankton at quarterly\\u000a intervals over a two-year period (#2 bolting cloth on Clarke-Bumpus samplers for 1-hour tows). The principal species were\\u000a counted from 20-foot depth intervals and for 13 channel stations distributed from the Atlantic Ocean to fresh water. Accompanying\\u000a hydrographic data were taken

L. E. Cronin; Joanne C. Daiber; E. M. Hulbert

1962-01-01

351

Carbon cycling in South-East Australian estuaries  

Microsoft Academic Search

Our conceptual understanding of estuarine carbon cycling is based predominantly on northern hemisphere temperate systems which differ from south-east Australian estuaries in many ways. Further, significant information gaps exist in our understanding of the estuarine carbon cycle, in particular the biogeochemical cycling of dissolved organic carbon (DOC) and air-water fluxes of CO2. The aim of this study was to measure

Damien Troy Maher

2011-01-01

352

Effects of wave forcing on a subterranean estuary  

NASA Astrophysics Data System (ADS)

Wave and tide are important forcing factors that typically coexist in coastal environments. A numerical study was conducted to investigate individual and combined effects of these forces on flow and mixing processes in a nearshore subterranean estuary. A hydrodynamic model based on the shallow water equations was used to simulate dynamic sea level oscillations driven by wave and tide. The oscillating sea levels determined the seaward boundary condition of the coastal aquifer, where variably saturated, variable density flow was modeled. The simulation results showed that waves induced an onshore upward tilt in the phase-averaged sea level (wave setup). The resulting hydraulic gradient generated pore water circulations in the nearshore zone of the coastal aquifer, which led to formation of an upper saline plume (USP) similar to that formed due to tides. However, mixing of recirculating seawater in the USP with underlying fresh groundwater was less intensive under the high-frequency wave oscillations. In the case of combined forcing, wave-induced circulations coupled with the intratidal flows strengthened the averaged, circulating pore water flows in the nearshore zone over the tidal period. The circulating flows increased exchange between the subterranean estuary and ocean, contributing 61% of the total submarine groundwater discharge for the simulated condition in comparison with the 40% and 49% proportions caused by the same but separate tidal and wave forcing, respectively. The combined forces also created a more extensive USP with the freshwater discharge zone shifted farther seaward. The freshwater flow paths in the intertidal subterranean estuary were modified with a significant increase in the associated transit times. The interplay of wave and tide led to increased mixing between discharging fresh groundwater and recirculating seawater. These results further demonstrate the complexity of nearshore groundwater systems and have implications for future investigations on the fate of land-sourced chemicals in the subterranean estuary prior to discharge to the ocean.

Xin, Pei; Robinson, Clare; Li, Ling; Barry, D. A.; Bakhtyar, R.

2010-12-01

353

Acidification of Lower St. Lawrence Estuary Bottom Waters  

Microsoft Academic Search

Accumulation of metabolic CO2 can acidify marine waters above and beyond the ongoing acidification of the ocean by anthropogenic CO2. The impact of respiration on carbonate chemistry and pH is most acute in hypoxic and anoxic basins, where metabolic CO2 accumulates to high concentrations. The bottom waters of the Lower St. Lawrence Estuary (LSLE), where persistently severe hypoxia has developed

Alfonso Mucci; Michel Starr; Denis Gilbert; Bjorn Sundby

2011-01-01

354

Environmental contaminants in bald eagles in the Columbia River estuary  

Microsoft Academic Search

Eggs, blood, and carcasses of bald eagles (Haliaeetus leucocephalus) and fish were collected and breeding success of eagles was monitored in the Columbia River estuary, 1980-87, to determine if contaminants were having an effect on productivity. High levels of dichloro diphenyl dichloroethylene (DDE), polychlorinated biphenyls (PCB's), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were found in eggs, blood from adults, and 2 eagle carcasses.

R. G. Anthony; M. G. Garrett; C. A. Schuler

1993-01-01

355

Sequential data assimilation in an upwelling influenced estuary  

Microsoft Academic Search

We have evaluated the impact of assimilating chlorophyll, nitrate, phosphate, silicate and ammonium into a coupled 1D hydrodynamic ecosystem model (GOTM-ERSEM) in an upwelling influenced estuary. The assimilation method chosen is the Ensemble Kalman Filter (EnKF), which has been demonstrated to improve field estimates of key variables (chlorophyll, nutrients) for bulk algal bloom prediction. The 1D model has been set

R. Torres; J. I. Allen; F. G. Figueiras

2006-01-01

356

Wave-current interactions in a tide dominated estuary  

NASA Astrophysics Data System (ADS)

There is a need to understand the interactions of waves and currents in the nearshore and estuarine areas. By using observational data and an advanced model an assessment of the wave-current interactions was performed in a hypertidal estuary. The circulation model includes both barotropic and baroclinic processes arising from tides, rivers and atmospheric forcing. It is coupled to a spectral wave model and a turbulence model. Waves within the estuary are strongly modulated by the tide. Significant wave height and period are mainly controlled by time-varying water depth, but wave periods are also affected by a Doppler shift produced by the current. The major-axis depth-averaged current component is tidally dominated and wave-induced processes do not have a significant effect on it. However, the inclusion of wave effects, in particular 3D radiation stress, improves the depth-averaged minor-axis (transverse) current component. The residual currents show a clear two-layer system, indicating that the baroclinic river influence is the dominant process. The wave effects are second order, but their consideration improves the long-term modelled residual circulation profile, specially the along estuary component. The main improvement appears when a 3-dimensional radiation stress coupling is considered. The 3D version of radiation stress produced better results than the 2D version. Within the estuary, wave setup has little effect on the storm surge, while 2-way wave-current interaction improved the wave simulation. Using a 3D Doppler shift further improved the model compared with using a 2D version.

Bolaños, Rodolfo; Brown, Jennifer M.; Souza, Alejandro J.

2014-09-01

357

Bedforms and Evolution of Tropical Estuaries: Examples from Northeastern Brazil  

NASA Astrophysics Data System (ADS)

This paper intends to show the geomorphological and sedimentary responses of tropical estuaries to meteorological and oceanographic forcing. The study area is located on the coastal zone of Rio Grande do Norte State, northeastern Brazil. This coast is under natural influence of waves and tides with a semidiurnal mesotidal regime and anthropogenic influence (urbanization, oil and salt industries, shrimp farms, and tourism). An operational methodology was developed using collection and analysis of an integrated dataset (comprising remote sensing, oceanographic, hy-droacoustic, and sedimentologic data). All data were integrated through a geographical infor-mation system database. The imaging of subaqueous features allowed the identification of differ-ent bedforms as well as submerged rocky outcrops. Four main groups of bedforms were identi-fied: 2D and 3D large dunes, ripples and flat bottom, and rocky outcrops as well. Rocky outcrops were correlated to Barreiras Formation and beachrocks. The estuarine channel is filled by Holocene sandy- to silt sediments, with sandy sediments in the main channel ranging from well-selected to selected grains, and silty sediments in the river margins. The integration and analysis of currents velocity and other physical parameters with bedforms characterization and different sedimentary textures in the study area allows a better knowledge of the active sedimentary processes, which are responsible for the formation of morphologic features of these estuaries. The evolution of estuary settings, led by the postglacial sea-level rise, is recorded in the subsurface an present-day riverbed. These results contribute to a better understanding of tropical estuaries.; Location of the study area

Vital, H.; Soares, C.; Rocha, G.; Pereira, T.; Eichler, P.

2012-12-01

358

Future variability of solute transport in a macrotidal estuary  

NASA Astrophysics Data System (ADS)

The physical controls on salt distribution and river-sourced conservative solutes, including the potential implications of climate change, are investigated referring to model simulations of a macrotidal estuary. In the UK, such estuaries typically react rapidly to rainfall events and, as such, are often in a state of non-equilibrium in terms of solute transport; hence are particularly sensitive to climate extremes. Sea levels are projected to rise over the 21st century, extending the salinity maximum upstream in estuaries, which will also affect downstream solute transport, promoting estuarine trapping and reducing offshore dispersal of material. Predicted 'drier summers' and 'wetter winters' in the UK will influence solute transport further still; we found that projected river flow climate changes were more influential than sea-level rise, especially for low flow conditions. Our simulations show that projected climate change for the UK is likely to increase variability in estuarine solute transport and, specifically, increase the likelihood of estuarine trapping during summer, mainly due to drier weather conditions. Future changes in solute transport were less certain during winter, since increased river flow will to some extent counter-act the effects of sea-level rise. Our results have important implications for non-conservative nutrient transport, water quality, coastal management and ecosystem resilience.

Robins, Peter E.; Lewis, Matt J.; Simpson, John H.; Howlett, Eleanor R.; Malham, Shelagh K.

2014-12-01

359

Carbon dioxide emissions from estuaries of northern and northeastern Brazil  

NASA Astrophysics Data System (ADS)

The carbon dioxide flux through the air-water interface of coastal estuarine systems must be quantified to understand the regional balance of carbon and its transport through adjacent coastal regions. We estimated and calculated the emissions of carbon dioxide (FCO2) and the partial pressure of CO2 (pCO2) values in 28 estuarine environments at a variety of spatial scales in the northern and northeastern regions of Brazil. The results showed a mean FCO2 (water to air) of 55 +/- 45 mmol.m-2.d-1. Additionally, a negative correlation between dissolved oxygen saturation and pCO2 was observed, indicating a control by biological processes and especially by organic matter degradation. This leads to increased dissolved CO2 concentration in estuarine waters which results in a pCO2 that reached 8,638 ?atm. Our study suggests that northern and northeastern Brazilian estuaries act as sources of atmospheric CO2. The range of pCO2 observed were similar to those found in inner estuaries in other places around the world, with the exception of a few semi-arid estuaries (Köppen climate classification - BSh) in which record low levels of pCO2 have been detected.

Noriega, Carlos; Araujo, Moacyr

2014-08-01

360

Dissolved oxygen conditions in northern Gulf of Mexico estuaries  

USGS Publications Warehouse

Because deficient dissolved oxygen (DO) levels may have severe detrimental effects on estuarine and marine life, DO has been widely used as an indicator of ecological conditions by environmental monitoring programs. The U.S. EPA's Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) monitored DO conditions in the estuaries of the Gulf of Mexico from 1991 to 1994. DO was measured in two ways: 1)instantaneous profiles from the surface to the bottom were taken during the day, and 2) continuous measurements were taken near the bottom at 15 min intervals for at least 12 h. This information was summarized to assess the spatial distribution and severity of DO conditions in these estuaries. Depending on the criteria used to define hypoxia (DO concentrations usually < 2 mg L-1 or 15 mg L-1) and the method by which DO is measured, we estimate that between 5.2 and 29.3% of the total estuarine area in the Louisianian Province was affected by low DO conditions.

Engle, V. D.; Kevin, Summers, J.; Macauley, J. M.

1999-01-01

361

Predicting habitat associations of five intertidal crab species among estuaries  

NASA Astrophysics Data System (ADS)

Intertidal crab assemblages that are active on the sediment surface of tropical estuaries during tidal exposure play an important role in many fundamental ecosystem processes. Consequently, they are critical contributors to a wide range of estuarine goods and services. However, a lack of understanding of their spatial organization within a large landscape context prevents the inclusion of intertidal crabs into generally applicable ecological models and management applications. We investigated spatial distribution patterns of intertidal crabs within and among eight dry tropical estuaries spread across a 160 km stretch of coast in North East Queensland, Australia. Habitat associations were modelled for five species based on photographic sampling in 40-80 sites per estuarine up- and downstream component: Uca seismella occurred in sites with little structure, bordered by low intertidal vegetation; Macrophthalmus japonicus occupied flat muddy sites with no structure or vegetation; Metopograpsus frontalis and Metopograpsus latifrons occupied sites covered with structure in more than 10% and 25% respectively. Finally, both Metopograpsus spp. and Metopograpsus thukuhar occupied rock walls. Habitat associations were predictable among estuaries with moderate to high sensitivity and low percentages of false positives indicating that simple, physical factors were adequate to explain the spatial distribution pattern of intertidal crabs. Results provide a necessary first step in developing generally applicable understanding of the fundamental mechanisms driving spatial niche organization of intertidal crabs within a landscape context.

Vermeiren, Peter; Sheaves, Marcus

2014-08-01

362

Counting on ?-Diversity to Safeguard the Resilience of Estuaries  

PubMed Central

Coastal ecosystems are often stressed by non-point source and cumulative effects that can lead to local-scale community homogenisation and a concomitant loss of large-scale ecological connectivity. Here we investigate the use of ?-diversity as a measure of both community heterogeneity and ecological connectivity. To understand the consequences of different environmental scenarios on heterogeneity and connectivity, it is necessary to understand the scale at which different environmental factors affect ?-diversity. We sampled macrofauna from intertidal sites in nine estuaries from New Zealand’s North Island that represented different degrees of stress derived from land-use. We used multiple regression models to identify relationships between ?-diversity and local sediment variables, factors related to the estuarine and catchment hydrodynamics and morphology and land-based stressors. At local scales, we found higher ?-diversity at sites with a relatively high total richness. At larger scales, ?-diversity was positively related to ?-diversity, suggesting that a large regional species pool was linked with large-scale heterogeneity in these systems. Local environmental heterogeneity influenced ?-diversity at both local and regional scales, although variables at the estuarine and catchment scales were both needed to explain large scale connectivity. The estuaries expected a priori to be the most stressed exhibited higher variance in community dissimilarity between sites and connectivity to the estuary species pool. This suggests that connectivity and heterogeneity metrics could be used to generate early warning signals of cumulative stress. PMID:23755252

de Juan, Silvia; Thrush, Simon F.; Hewitt, Judi E.

2013-01-01

363

Environmental contaminants in bald eagles in the Columbia River estuary  

SciTech Connect

Eggs, blood, and carcasses of bald eagles (Haliaeetus leucocephalus) and fish were collected and breeding success of eagles was monitored in the Columbia River estuary, 1980-87, to determine if contaminants were having an effect on productivity. High levels of dichloro diphenyl dichloroethylene (DDE), polychlorinated biphenyls (PCB's), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were found in eggs, blood from adults, and 2 eagle carcasses. Detectable levels of DDE and PCB's were found in blood of nestlings indicating they were exposed to these contaminants early in life. Increasing concentrations of DDE and PCB's with age also indicated accumulation of these contaminants. Adult eagles also had higher levels of mercury (Hg) in blood than subadults or young indicating accumulation with age. The high levels of DDE and PCB's were associated with eggshell thinning ([bar x] = 10%) and with productivity ([bar x] = 0.56 young/occupied site) that was lower than that of healthy populations (i.e., [ge]1.00 young/occupied site). DDE and PCB's had a deleterious effect on reproduction of bald eagles in the estuary. The role dioxins play in eagle reproduction remains unclear, but concentrations in eagle eggs were similar to those in laboratory studies on other species where dioxins adversely affected hatchability of eggs. Probable source of these contaminants include dredged river sediments and hydroelectric dams, and the proper management of each may reduce the amount of contaminants released into the Columbia River estuary. 46 refs., 1 fig., 4 tabs.

Anthony, R.G.; Garrett, M.G. (Oregon State Univ., Corvallis (United States)); Schuler, C.A. (Fish and Wildlife Service, Portland, OR (United States))

1993-01-01

364

Air-Sea Gas Transfer Velocity in a Shallow Estuary  

NASA Astrophysics Data System (ADS)

The air-sea transfer velocity of was investigated in a shallow estuary in March to July 2012, using eddy-covariance measurements of fluxes and measured air-sea partial-pressure differences. A data evaluation method that eliminates data by nine rejection criteria in order to heighten parametrization certainty is proposed. We tested the data evaluation method by comparing two datasets: one derived using quality criteria related solely to the eddy-covariance method, and the other derived using quality criteria based on both eddy-covariance and cospectral peak methods. The best parametrization of transfer velocity normalized to a Schmidt number of 600 was determined to be: where is the wind speed in m at 10 m; is based on fluxes calculated by the eddy-covariance method and including the cospectral peak method criteria. At low wind speeds, the transfer velocity in the shallow water estuary was lower than in other coastal waters, possibly a symptom of low tidal amplitude leading to low intensity water turbulence. High transfer velocities were recorded above wind speeds of 5 m , believed to be caused by early-breaking waves and the large fetch (6.5 km) of the estuary. These findings indicate that turbulence in both air and water influences the transfer velocity.

Mørk, Eva Thorborg; Sørensen, Lise Lotte; Jensen, Bjarne; Sejr, Mikael K.

2014-04-01

365

Flathead Renewable Energy Feasibility Study  

SciTech Connect

The study shall assess the feasibility of a commercial wind facility on lands selected and owned by the Salish and Kootenai Tribes and shall examine the potential for the development of solar and biomass resources located on Tribal Lands.

Belvin Pete: Ed McCarthy; Krista Gordon; Chris Bergen; Rhett Good

2006-10-03

366

(Feasibility study of the San Lorenzo River hydroelectric project)  

SciTech Connect

I travelled to San Jose, Costa Rica on July 8, 1990 to evaluate all of the completed elements of the ongoing feasibility study for the San Lorenzo River hydroelectric project. The feasibility study is being supported by ORNL under the Renewable Energy Applications and Training Project. The project is being studied for implementation by CONELECTRICAS, a consortium of rural electric cooperatives and the study itself is being conducted by BEL Engineering, a Costa Rican consulting firm under contract to CONELECTRICAS, USAID/PIC and NRECA.

Chronowski, R.A.

1990-07-19

367

Proceedings of the 2005 American Society for Engineering Education Annual Conference & Exposition Copyright ASEE 2005, American Society for Engineering Education.  

E-print Network

of continued automation and commercialized bio- nanotechnology on a corporate lifestyle. One visualized ASEE 2005, American Society for Engineering Education. feasible in a vastly expanded aerospace economy

368

Late-Quaternary morpho-sedimentology and submarine mass movements of the Betsiamites area, Lower St. Lawrence Estuary, Quebec, Canada  

E-print Network

-sedimentology multibeam bathymetry seismic reflection earthquakes St. Lawrence Estuary Betsiamites River A complex submarine geomorphology was revealed from multibeam bathymetry and seismic reflection surveys conducted between 2001 and 2007 in the Lower St. Lawrence Estuary offshore Betsiamites River, Quebec, Canada

Long, Bernard

369

Variation in tidal wetland plant diversity and composition within and among coastal estuaries: assessing the relative importance of environmental gradients  

EPA Science Inventory

Question: Does wetland plant composition vary more by estuarine type (differentiated by the degree of riverine versus oceanic influence) or habitat type within estuaries (defined by US National Wetlands Inventory [NWI] marsh classes)? Location: Oregon estuaries: Netarts Bay, Yaq...

370

RELATIONS OF FISH AND SHELLFISH DISTRIBUTIONS TO HABITAT AND WATER QUALITY IN THE MOBILE BAY ESTUARY, USA  

EPA Science Inventory

The Mobile Bay estuary provides rich habitat for many fish and shellfish, including those identified as economically and ecologically important. The National Estuary Program has focused on restoration of degraded estuarine habitat on which these species depend. To support this ...

371

Effects of artificial openings of intermittently opening estuaries on macroinvertebrate assemblages of the entrance barrier  

NASA Astrophysics Data System (ADS)

Intermittently opening estuaries are artificially opened to manage flood risk, water quality, recreational amenity, and fisheries; however, the ecological impacts of this management technique are incompletely understood. During 2001 and 2004, this study assessed the impacts of artificial openings on the macroinvertebrates of entrance barriers of intermittently opening estuaries in New South Wales (Australia). In 2001 macroinvertebrates were sampled once before artificial opening and 9 and 25 d after re-formation of the entrance barrier. A multiple before-after-control-impact analysis found that, although entrance barriers were destroyed by the artificial openings and then re-formed naturally by wave action, significant interactions for taxonomic richness, density of the amphipod Paracalliope australis (Gammaridae) and density of the gastropod mollusc Aschoris victoriae (Hydrobiidae) meant that the effects of this disturbance could not be distinguished from the natural variations that occurred in unopened estuaries. Multivariate analyses found that assemblages at both opened and unopened estuaries changed from before to after the openings, and the magnitude of the dissimilarity between times varied between estuaries. In 2004, macroinvertebrates were sampled on three randomly selected days within each of three periods (before, 3 d and 42 d after) at one opened and three unopened estuaries. Asymmetrical analysis of this modified before-after-control-impact study found that the change in taxonomic richness at the opened estuary from before to after opening did not differ from temporal changes that occurred in unopened estuaries. Short-term variation (i.e. between days) in total density of macroinvertebrates and density of P. australis in the re-formed entrance barrier of the opened estuary also did not differ from the variation in the control estuaries. Additionally, assemblage structure was not significantly changed by the opening and assemblages at two control estuaries were also unchanged over the same time. Individual taxa and assemblages of macroinvertebrates in entrance barriers of these intermittently open estuarine systems appear to be resilient to the habitat disturbance caused by artificial openings.

Gladstone, William; Hacking, Nicole; Owen, Vanessa

2006-05-01

372

The hydrodynamic response of the York River estuary to Tropical Cyclone Isabel, 2003  

NASA Astrophysics Data System (ADS)

Hurricane Isabel made landfall along the North Carolina coast on September 18, 2003 (UTC 17:00) and the storm surge exceeded 2.0 m in many areas of the Chesapeake Bay and in the York River estuary. River flooding occurred subsequently, and the peak river discharge reached 317 and 104 m 3 s -1 in the Pamunkey and Mattaponi rivers, respectively. The York River estuary experienced both storm surge and river flooding during the event and the estuary dynamics changed dramatically. This study investigates the hydrodynamics of the York River estuary in response to the storm surge and high river inflows. A three-dimensional model was used to investigate the changes of estuarine stratification, longitudinal circulation, salt flux mechanisms, and the recovery time required for the estuary to return to its naturally evolved condition without the storm. Results show that the salt flux was mainly caused by advection, which was induced by the barotropic gradient during the storm event. The net salt flux increased by a factor of 30 during the rise of the storm surge. However, the large amount of salt transported into the estuary was quickly transported out of the estuary as the barotropic gradient reversed during the descent of the storm surge. Subsequent high freshwater inflow influenced the estuarine circulation substantially. The estuary changed from a partially mixed estuary to a very stratified estuary for a prolonged period. The model results show that it will take about 4 months for the estuary to recover to its naturally evolved salinity distribution after the impacts of the storm surge and freshwater pulse.

Gong, Wenping; Shen, Jian; Reay, William G.

2007-07-01

373

Feasibility analysis of recycling radioactive scrap steel  

SciTech Connect

The purpose of this study is to: (1) establish a conceptual design that integrates commercial steel mill technology with radioactive scrap metal (RSM) processing to produce carbon and stainless steel sheet and plate at a grade suitable for fabricating into radioactive waste containers; (2) determine the economic feasibility of building a micro-mill in the Western US to process 30,000 tons of RSM per year from both DOE and the nuclear utilities; and (3) provide recommendations for implementation. For purposes of defining the project, it is divided into phases: economic feasibility and conceptual design; preliminary design; detail design; construction; and operation. This study comprises the bulk of Phase 1. It is divided into four sections. Section 1 provides the reader with a complete overview extracting pertinent data, recommendations and conclusions from the remainder of the report. Section 2 defines the variables that impact the design requirements. These data form the baseline to create a preliminary conceptual design that is technically sound, economically viable, and capitalizes on economies of scale. Priorities governing the design activities are: (1) minimizing worker exposure to radionuclide hazards, (2) maximizing worker safety, (3) minimizing environmental contamination, (4) minimizing secondary wastes, and (5) establishing engineering controls to insure that the plant will be granted a license in the state selected for operation. Section 3 provides details of the preliminary conceptual design that was selected. The cost of project construction is estimated and the personnel needed to support the steel-making operation and radiological and environmental control are identified. Section 4 identifies the operational costs and supports the economic feasibility analysis. A detailed discussion of the resulting conclusions and recommendations is included in this section.

Nichols, F. [Manufacturing Sciences Corp., Woodland, WA (United States); Balhiser, B. [MSE, Inc., Butte, MT (United States); Cignetti, N. [Cignetti Associates, North Canton, OH (United States)] [and others

1995-09-01

374

College of Engineering College of Engineering  

E-print Network

College of Engineering College of Engineering Office in Engineering Building, Room 202 (970) 491 UNDERGRADUATE MAJORS Biomedical Engineering Chemical and Biological Engineering Civil Engineering Computer Engineering Electrical Engineering Engineering Science Environmental Engineering Mechanical Engineering

Collett Jr., Jeffrey L.

375

Spartina alterniflora invasions in the Yangtze River estuary, China: An overview of current status and ecosystem effects  

Microsoft Academic Search

The Yangtze River estuary is an important ecoregion. However, Spartina alterniflora, native to North America, was introduced to the estuary in the 1990s through both natural dispersal and humans and now it is a dominant species in the estuarine ecosystems, with its invasions leading to multiple consequences to the estuary. S. alterniflora had great competitive effects on native species, including

Bo Li; Chengz-hang Liao; Xiao-dong Zhang; Hui-li Chen; Qing Wang; Zhong-yi Chen; Xiao-jing Gan; Ji-hua Wu; Bin Zhao; Zhi-jun Ma; Xiao-li Cheng; Li-fen Jiang; Jia-kuan Chen

2009-01-01

376

Ecological Aspects of the Annapolis Estuary With Specific Reference to Operational Effects of the Annapolis Tidal Power Station  

Microsoft Academic Search

Results of physico-chemical and biological studies in the Annapolis Estuary are reviewed with reference to possible environmental effects of the Annapolis Tidal Power Station. Tidal barrage construction in 1960 transformed a vertically homogenous type of estuary into a highly stratf- fled salt wedge estuary with a reduced tidal range. Stratification is highly stable in the lower river and variable in

Anna M. Redden; Graham R. Daborn; Robert S. Gregory

377

Impact of the river Liffey discharge on nutrient and chlorophyll concentrations in the Liffey estuary and Dublin Bay (Irish Sea)  

Microsoft Academic Search

Temperature, salinity, nutrients (total oxidised nitrogen (TON), ammonium (NH4) and orthophosphate (PO4)) and chlorophyll a were monitored in the Liffey estuary and Dublin Bay from June 2000 to June 2003. Four groups of sites were defined comprising the upper estuary (Gp. I), the outer estuary (Gp. III) with a small set (Gp. II) of sites between Groups I and III

T. G. O'Higgins; J. G. Wilson

2005-01-01

378

Relationships between Zoo and Phytoplankton in a Warm-temperate, Semi-permanently Closed Estuary, South Africa  

Microsoft Academic Search

Seasonal surveys were carried out in the shallow, well-conserved temporarily open Nyara Estuary in the Eastern Cape, South Africa. Although temporarily open estuaries constitute over 70% of estuaries in South Africa, few data are available on the structure and functioning of these systems in the region. The main aim of the study was to test the hypothesis that owing to

R. Perissinotto; D. R. Walker; P. Webb; T. H. Wooldridge; R. Bally

2000-01-01

379

Effect of wind events on phytoplankton blooms in the Pearl River estuary during summer  

Microsoft Academic Search

The Pearl River estuary fuels phytoplankton productivity in the estuarine coastal waters in the oligotrophic South China Sea. Cruises were conducted to investigate the spatial distribution of primary productivity, and two size fractionations (5?m) of chlorophyll in the Pearl River estuary and across the coastal plume south of Hong Kong during the season of high river discharge (July, 1999 and

Kedong Yin; Jianlin Zhang; Pei-Yuan Qian; Weijun Jian; Liangmin Huang; Jianfang Chen; Madeline C. S. Wu

2004-01-01

380

Evaluation of sampling strategies to characterize dissolved oxygen conditions in northern Gulf of Mexico estuaries  

Microsoft Academic Search

Dissolved oxygen was continuously monitored in eight sites of northern Gulf of Mexico estuaries in August, 1990. Monte Carlo analyses on subsamples of the data were used to evaluate several commonly used monitoring strategies. Monitoring strategies which involve single point sampling of dissolved oxygen may often misclassify an estuary as having good water quality. In the case of shallow, often

J. Kevin Summers; Virginia D. Engle

1993-01-01

381

Sedimentary development of the Pearl River Estuary based on seismic stratigraphy  

Microsoft Academic Search

The Pearl River Estuary in the Southern China was studied both by applying concepts of seismic stratigraphy to the interpretation of high resolution seismic profiles and by correlating with borehole records. The correlation between seismic facies and borehole stratigraphy of the estuary enables to propose a seismic stratigraphy model of the estuarine infill. The stratigraphy and evolution of the Holocene

Cheng Tang; Di Zhou; Rudolf Endler; Jinqing Lin; Jan Harff

2010-01-01

382

River discharge, sediment transport and exchange in the Tana Estuary, Kenya  

Microsoft Academic Search

This study focuses on sediment transport and exchange dynamics in the 27km2 Tana Estuary located at Kipini in the north Kenya coast. The estuary is drained by the Tana River, which contributes more than 50% of the total river discharges into the Kenyan sector of the Indian Ocean. The study involved measurement of river discharges, estuarine flood–ebb tidal discharges, total

J. U. Kitheka; M. Obiero; P. Nthenge

2005-01-01

383

Loss of diversity of ammonia-oxidizing bacteria correlates with increasing salinity in an estuary system  

Microsoft Academic Search

Summary Ammonia-oxidizing bacteria (AOB) play an important role in nitrogen cycling in estuaries, but little is known about AOB diversity, distribution and activity in rela- tion to the chemical and physical changes encoun- tered in estuary systems. Although estuarine salinity gradients are well recognized to influence microbial community structure, few studies have examined the influence of varying salinity on the

Anne E. Bernhard; Thomas Donn; Anne E. Giblin; David A. Stahl

2005-01-01

384

RELATIONSHIPS BETWEEN SEAGRASSES, BENTHIC MACROALGAE AND NUTRIENTS IN A PACIFIC NORTHWEST ESTUARY  

EPA Science Inventory

Pacific Northwest estuaries are characterized by large tidal ranges (2-3 m) that routinely expose submerged aquatic vegetation (SAV) such as seagrass and benthic macroalgae. The dominant native seagrass in PNW estuaries is the eelgrass Zostera marina. However, in recent decades...

385

NAME: Salt Creek Estuary Restoration LOCATION: Salt Creek Watershed, Clallam County, Washington  

E-print Network

NAME: Salt Creek Estuary Restoration LOCATION: Salt Creek Watershed, Clallam County, Washington Federal funds $0 PROJECT DESCRIPTION: The Salt Creek Estuary Reconnection project will significantly enhance tidal and fluvial hydrology to 22.5 acres of salt marsh, which will return the salt marsh to its

US Army Corps of Engineers

386

Water pollution in estuaries and coastal zones. (Latest citations from the NTIS bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning the studies of water pollution in estuaries and coastal zones. Citations examine the development, management, and protection of estuary and coastal resources. Topics include pollution sources, environmental monitoring, water chemistry, eutrophication, models, land use, government policy, and laws and regulations. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

NONE

1996-02-01

387

Estuaries Vol. 20, No. 2, p. 381-390 June 1997 Carbon Dioxide Concentration and Atmospheric  

E-print Network

2)in the tidal-freshwaterportion of the Hudson River Estuary over a 3.5~yr period. At all times tbe, we estimate that the Hudson releases CO, at a rate of 70-162 g C m-2 yt-' from the river studied the tidal freshwater portion of the Hudson River Estuary from Albany, New York, to the Tappan Zee

388

Bioavailability of heavy metals monitoring water, sediments and fish species from a polluted estuary  

Microsoft Academic Search

Concentrations of heavy metals (Cu, Zn, Cd, Pb and As) were measured in water, sediment and two fish species, Sparus aurata and Solea senegalensis, from the estuary of Tinto and Odiel rivers in Huelva (Spain), one of the most metallic polluted estuaries in Europe.As a forward step to understand metal bioavailability and assess the potential impact on aquatic biota, a

Juan J. Vicente-Martorell; María D. Galindo-Riaño; Manuel García-Vargas; María D. Granado-Castro

2009-01-01

389

Second international symposium on the biogeochemistry of model estuaries: Estuarine processes in global change  

SciTech Connect

This report consists of abstracts of papers presented at the symposium of Biogeochemistry. The main topics discussed at the meeting are; nutrient and mineral cycling, trace element distribution, sources and sinks of estuaries, sedimentation, importance of organic matter, and other biogeochemical processes of estuaries.

Not Available

1991-12-31

390

Sea ice, hydrological, and biological processes in the Churchill River estuary region, Hudson Bay  

Microsoft Academic Search

A conceptual scheme for the transition from winter to spring is developed for a small Arctic estuary (Churchill River, Hudson Bay) using hydrological, meteorological and oceanographic data together with models of the landfast ice. Observations within the Churchill River estuary and away from the direct influence of the river plume (Button Bay), between March and May 2005, show that both

Z. A. Kuzyk; R. W. Macdonald; M. A. Granskog; R. K. Scharien; R. J. Galley; C. Michel; D. Barber; G. Stern

2008-01-01

391

Modelling Macroalgae Productivity In An Estuary. A Biorremediation To Nutrient Discharges In The Ecosystems  

Microsoft Academic Search

Enhanced nutrient load to estuaries and coastal waters due to anthropogenic activities is damaging aquatic ecosystems, resulting in water pollution and eutrophication prob- lems. It is important to quantify the production of photosynthetic organisms, as they play an important role in controlling nitrogen removal and nitrogen fluxes between the sediments and the water column. In turbid estuaries, such as those

A. Alvera-Azcárate; J. G. Ferreira; J. P. Nunes

2002-01-01

392

Origin and biochemical cycling of particulate nitrogen in the Mandovi estuary  

Microsoft Academic Search

Mandovi estuary is a tropical estuary strongly influenced by the southwest monsoon. In order to understand, sources and fate of particulate organic nitrogen, suspended particulate matter (SPM) collected from various locations, was analyzed for particulate organic carbon (POC) and particulate organic nitrogen (PON), ?13CPOC, total hydrolysable amino acid enantiomers (l- and d- amino acids) concentration and composition. ?13CPOC values were

Loreta Fernandes

2011-01-01

393

The Plum Island Ecosystems (PIE) research site consists of a coupled watershed and estuary in northeastern  

E-print Network

The Plum Island Ecosystems (PIE) research site consists of a coupled watershed and estuary Plum Island estuary. (Photo: Chuck Hopkinson) Plum Island Ecosystems Long Term Ecological Research. (Photo: Christian Picard) #12;Our research on watersheds focuses on the water and nitrogen cycles

Vallino, Joseph J.

394

DEVELOPING NUTRIENT CRIETERIA FOR ESTUARIES WITH VARIABLE OCEAN INPUTS: AN EXAMPLE FROM THE PACIFIC NORTHWEST  

EPA Science Inventory

Estuaries in the Pacific Northwest have major intraannual and within estuary variation in sources and magnitudes of nutrient inputs. To develop an approach for setting nutrient criteria for these systems, we conducted a case study for Yaquina Bay, OR based on a synthesis of resea...

395

Relationships between watershed Stressors and sediment contamination in Chesapeake Bay estuaries  

Microsoft Academic Search

Three methods for assessing the relationships between estuarine sediment contaminant levels and watershed Stressors for 25 Chesapeake Bay sub-estuaries were compared. A geographic information system (GIS) was used to delineate watersheds for each sub-estuary and analyze land use pattern (area and location of developed, herbaceous and forested land) and point source pollution (annual outflow and contaminant loading) using three landscape

Randy L. Comeleo; John F. Paul; Peter V. August; Jane Copeland; Carol Baker; Stephen S. Hale; Richard W. Latimer

1996-01-01

396

The importance of tidal creek ecosystems Keywords: Estuary; Tidal creek; Pollution  

E-print Network

.g. the Chesapeake Bay, the Albemarle�Pamlico Sound System, Florida Bay, to name a few). These better-known large Marine Biology and Ecology 298 (2004) 145�149 #12;estuaries such as the ICW, Laguna Madre, Chesapeake BayPreface The importance of tidal creek ecosystems Keywords: Estuary; Tidal creek; Pollution Tidal

Mallin, Michael

397

Susceptibility of east coast estuaries to nutrient discharges: Passamaquoddy Bay to Chesapeake Bay. Summary report  

Microsoft Academic Search

This is the third report in a series being developed to assist the US EPA implement its Near Coastal Waters and National Estuary Programs. It summarizes estimates of the relative susceptibility and status of 17 estuaries on the East Coast from Maine through Virginia, with respect to nutrient-related pollution. The information is intended to increase understanding of coastal environmental problems

H. Quinn; J. P. Tolson; C. J. Klein; S. P. Orlando; C. Alexander

1989-01-01

398

Comparasion of finite difference and finite element hydrodynamic models applied to the Laguna Madre Estuary, Texas  

E-print Network

The U.S. Geological Survey Surface Water Flow and Transport Model in Two-Dimensions (SV*9FT2D) model was applied to the northern half of the Laguna Madre Estuary. SW=D is a two dimensional hydrodynamic and transport model for well-mixed estuaries...

McArthur, Karl Edward

2012-06-07

399

Distribution, transport and exchanges of fine sediment, with tidal power implications: Severn Estuary, UK  

Microsoft Academic Search

The Severn, a hypertidal, high turbidity estuary, has a bed largely stripped of unconsolidated sediment. Its inter-tidal zone is mainly mudflats, the universal erosional trend of which is now proven. These are a source for sub-tidal mud accumulations in Newport Deep, much of Bridgwater Bay, less so in Bristol Deep and Cardiff Roads. The main estuary turbidity maximum is dominated

R. Kirby

2010-01-01

400

SEASONAL ABUNDANCE AND DISTRIBUTION OF BIRDS ON THE SWARTKOPS ESTUARY, PORT ELIZABETH  

Microsoft Academic Search

Martin, A. P. & Baird, D. 1987. Seasonal abundance and distribution of birds on the Swartkops estuary, Port Elizabeth. Ostrich 58:122-134. Counts of estuarine birds were made on the Swartkops estuary, Port Elizabeth, between September 1983 and August 1985. Seasonal variations in the numbers of both migrant and resident species were investigated; in the austral summer, over 4000 birds were

A. P. Martin; D. Baird

1987-01-01

401

Trace metals transport and behaviour in the Mediterranean estuary of Acheloos river  

Microsoft Academic Search

The concentration levels and the chemical behaviour of trace metals during their transport, were studied in the estuary of the Acheloos river, in western Greece. It is a typical, non tidal and stratified Mediterranean estuary which, although is not heavily polluted, is affected by a lot of human activities (dams, agriculture, fishing, etc.) that, in combination with its hydrological and

M. Dassenakis; M. Scoullos; A. Gaitis

1997-01-01

402

An Idealized Model and Systematic Process Study of Oxygen Depletion in Highly Turbid Estuaries  

E-print Network

An Idealized Model and Systematic Process Study of Oxygen Depletion in Highly Turbid Estuaries S. A The sensitivity of oxygen depletion in turbid estuaries to parameters like freshwater discharge, depth of DO with SSC and temperature. Modeled DO closely tracks changes to the estuarine turbidity zone (ETZ

Talke, Stefan

403

Variations and Dependency of Sedimentary Processes and Morphology of the Hudson River Estuary  

Microsoft Academic Search

The morphology of rivers and estuaries is controlled by many factors including bedrock geology, flow conditions, and sediment input. The 240 km long Hudson River Estuary crosses different types of bedrock, and its sediment transport is strongly influenced by tidal currents and strong runoff events. The small contribution of tributary input in the estuarine part of the Hudson River allows

F. O. Nitsche; R. Bell; W. B. Ryan; S. M. Carbotte; C. Bertinato

2004-01-01

404

An approach to developing nutrient criteria for Pacific Northwest Estuaries: A case study  

EPA Science Inventory

This presentation provides an overview of an approach to developing nutrient criteria for Pacific Northwest (PNW) estuaries, based on a case study of Yaquina Estuary, Oregon. The approach is based on a synthesis of research from field studies, analyses of historical trends in wat...

405

WestuRe: U.S. Pacific Coast estuary/watershed data and R tools  

EPA Science Inventory

There are about 350 estuaries along the U.S. Pacific Coast. Basic descriptive data for these estuaries, such as their size and watershed area, are important for coastal-scale research and conservation planning. However, this information is spread among many sources and can be dif...

406

Developing Nitrogen Load-Eelgrass Response Relationshups for New England Estuaries  

EPA Science Inventory

We have accumulated and analyzed eelgrass areal extent data for 67 estuaries from three New England states. To our knowledge this is the largest data set of its kind. Previous comparative studies have utilized data from a far smaller number of estuaries (ten or less) to develop e...

407

Demonstration and Hands-on Exercises with the Estuary Data Mapper  

EPA Science Inventory

The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for applications of the Clean Water Act in coastal management. E-Estuary has three elements: an estuarine geo-referenced relational database, watershed GIS coverages, and tools t...

408

Pollutant fate and spatio-temporal variability in the choptank river estuary: Factors influencing water quality  

Microsoft Academic Search

Restoration of the Chesapeake Bay, the largest estuary in the United States, is a national priority. Documentation of progress of this restoration effort is needed. A study was conducted to examine water quality in the Choptank River estuary, a tributary of the Chesapeake Bay that since 1998 has been classified as impaired waters under the Federal Clean Water Act. Multiple

David Whitall; W. Dean Hively; Andrew K. Leight; Cathleen J. Hapeman; Laura L. McConnell; Thomas Fisher; Clifford P. Rice; Eton Codling; Gregory W. McCarty; Ali M. Sadeghi; Anne Gustafson; Krystyna Bialek

2010-01-01

409

EFFECTS OF EROSION AND MACROALGAE ON INTERTIDAL EELGRASS (ZOSTERA MARINA) IN A NORTHEASTERN PACIFIC ESTUARY (USA)  

EPA Science Inventory

Eelgrass (Zostera marina) in open-coast northeastern Pacific estuaries is primarily intertidal, yet little research has been done on the natural factors controlling its upper intertidal growth limits. This two-year study in the Yaquina Estuary (Newport, Oregon, USA) evaluated the...

410

Potential Climate-Induced Runoff Changes and Associated Uncertainty in Four Pacific Northwest Estuaries  

EPA Science Inventory

As part of a larger investigation into potential impacts of climate change on estuarine habitats in the Pacific Northwest (PNW), we estimated changes in freshwater inputs into four estuaries. These were the Coquille River estuary, the South Slough of Coos Bay, and the Yaquina Bay...

411

Transport of fallout and reactor radionuclides in the drainage basin of the Hudson River estuary  

SciTech Connect

The transport and fate of Strontium 90, Cesium 137 and Plutonium 239, 240 in the Hudson River Estuary is discussed. Rates of radionuclide deposition and accumulation over time and space are calculated for the Hudson River watershed, estuary, and continental shelf offshore. 37 references, 7 figures, 15 tables. (ACR)

Simpson, H.J.; Linsalata, P.; Olsen, C.R.

1982-01-01

412

MODELING FISH AND SHELLFISH DISTRIBUTIONS IN THE MOBILE BAY ESTUARY, USA  

EPA Science Inventory

Estuaries in the Gulf of Mexico provide rich habitat for many fish and shellfish, including those that have been identified as economically and ecologically important. For the Mobile Bay estuary, we developed statistical models to relate distributions of individual species and sp...

413

Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ Measurements  

E-print Network

Mercury Dynamics in a San Francisco Estuary Tidal Wetland: Assessing Dynamics Using In Situ the tidally driven exchange of mercury (Hg) between the waters of the San Francisco estuary and Browns Island, respectively--together predicted 94 % of the observed variability in measured total mercury concentra- tion

Boss, Emmanuel S.

414

Chromium speciation in tannery effluent—II. Speciation in the effluent and in a receiving estuary  

Microsoft Academic Search

The forms and transformations of chromium were characterised in the effluent of an Irish tannery before and after discharge into an estuary. The three primary effluent streams in the tannery were studied, i.e. the chrome and sulphide streams and the final composite effluent. Chromium was fully speciated in the final effluent, the discharge plume, and in the estuary outside discharge

Andrew R. Walsh; John O'Halloran

1996-01-01

415

Report on benthic survey/sampling at Coquille Estuary, OR: June 30-July 3, 2008  

EPA Science Inventory

Zostera japonica is a non-native seagrass first reported in the PNW in Willapa Bay in 1957 (Harrison and Bigley 1982). Since the, Z. japonica has been reported from 16 estuaries in the PNW (Lee and Reusser 2007), including the Yaquina Estuary in 1974-1975 (Bayer 1996). Besides ...

416

Seasonal Use of a New England Estuary by Foraging Contingents of Migratory Striped Bass  

Microsoft Academic Search

Using acoustic telemetry on migratory striped bass Morone saxatilis in Plum Island Estuary (PIE), Massachusetts, we found that striped bass (335–634 mm total length) tagged in the spring and summer of 2005 (n = 14) and 2006 (n = 46) stayed in the estuary for an average of 66.0 d in 2005 and 72.2 d in 2006. Striped bass spent

Sarah M. Pautzke; Martha E. Mather; John T. Finn; Linda A. Deegan; Robert M. Muth

2010-01-01

417

Influence of sea level rise on iron diagenesis in an east Florida subterranean estuary  

Microsoft Academic Search

Subterranean estuary occupies the transition zone between hypoxic fresh groundwater and oxic seawater, and between terrestrial and marine sediment deposits. Consequently, we hypothesize, in a subterranean estuary, biogeochemical reactions of Fe respond to submarine groundwater discharge (SGD) and sea level rise. Porewater and sediment samples were collected across a 30-m wide freshwater discharge zone of the Indian River Lagoon (Florida,

Moutusi Roy; Jonathan B. Martin; Jennifer Cherrier; Jaye E. Cable; Christopher G. Smith

2010-01-01

418

Denitrification Capacity in a Subterranean Estuary below a Rhode Island Fringing Salt Marsh  

E-print Network

by nitrogen (N) loading from direct groundwater discharge. The subterranean estuary, the mixing zone of fresh into the subterranean estuary (in situ push-pull method) to evaluate the denitrification capacity of the saturated zone approached the high and low marsh, the hydraulic gradient increased and deep groundwater upwelled

Gold, Art

419

Changes in a temperate estuary during the filling of the biggest European dam  

Microsoft Academic Search

This study aimed to determine whether and how the disruption of river flow, during the filling of the Alqueva dam, influenced the variability of abiotic and biotic factors in the Guadiana estuary, particularly the abundance and distribution of anchovy eggs. River inflow was found to be the most important factor in determining abiotic and biotic variability in the Guadiana estuary.

Pedro Morais; Maria Alexandra Chícharo; Luís Chícharo

2009-01-01

420

Freshwater and marine coupling in estuaries of the Mississippi River deltaic plain  

Microsoft Academic Search

The estuaries of Louisiana's Mississippi River deltaic plain (MRDP) exhibit sharp physical and biological contrasts due to their different successional stages in delta development. The Atchafalaya- Fourleague Bay complex is a young deltaic system with high freshwater and sediment inputs. The area has been undergoing rapid land building since 1973. The Barataria Basin estuary occupies a deltaic land mass which

CHRISTOPHER J. MADDEN; JOHN W. DAY; JOHN M. RANDALL

1988-01-01

421

Trace element cycling in a subterranean estuary: Part 1. Geochemistry of the permeable sediments  

Microsoft Academic Search

Subterranean estuaries are characterized by the mixing of terrestrially derived groundwater and seawater in a coastal aquifer. Subterranean estuaries, like their river water-seawater counterparts on the surface of the earth, represent a major, but less visible, hydrological and geochemical interface between the continents and the ocean. This article is the first in a two-part series on the biogeochemistry of the

Matthew A. Charette; Edward R. Sholkovitz; Colleen M. Hansel

2005-01-01

422

The Ecological and Environmental Characteristics and Conservation of the Wetlands in the Changjiang Estuary, China  

Microsoft Academic Search

The natural wetlands in the Changjiang Estuary, China are important ecologically. The total area of the wetlands in the Changjiang Estuary amounts to 215000 ha. The wetlands consist of littoral and sandy estuarine island areas, and are rich in biological resources. There are 136 species of vascular plant, 150 species of bird, and 68 species of benthic macro-invertebrate in the

X. Z. Yuan; H. Liu; J. J. Lu

2002-01-01

423

Transport of dissolved nutrients and chlorophyll a in a tropical estuary, southwest coast of India.  

PubMed

Intra-tidal variability in the transport of materials through the Cochin estuary was studied over successive spring and neap tides to estimate the export fluxes of nutrients and chlorophyll a into the adjoining coastal zone. The results showed that there was a substantial increase in the freshwater flow into the estuary following heavy rains (~126 mm) prior to the spring tide observations. The estuary responded accordingly with a relatively larger export through the Cochin inlet during spring tide over neap tide. Despite an increased freshwater discharge during spring tide, the export fluxes of phosphate and ammonia were high during neap tide due to their input into the estuary through anthropogenic activities. The significance of this study is that the export fluxes from the Cochin estuary could be a major factor sustaining the spectacular monsoon fishery along the southwest coast of India. PMID:24771463

Lallu, K R; Fausia, K H; Vinita, J; Balachandran, K K; Naveen Kumar, K R; Rehitha, T V

2014-08-01

424

How We Design Feasibility Studies  

PubMed Central

Public health is moving toward the goal of implementing evidence-based interventions. To accomplish this, there is a need to select, adapt, and evaluate intervention studies. Such selection relies, in part, on making judgments about the feasibility of possible interventions and determining whether comprehensive and multilevel evaluations are justified. There exist few published standards and guides to aid these judgments. This article describes the diverse types of feasibility studies conducted in the field of cancer prevention, using a group of recently funded grants from the National Cancer Institute. The grants were submitted in response to a request for applications proposing research to identify feasible interventions for increasing the utilization of the Cancer Information Service among underserved populations. PMID:19362699

Bowen, Deborah J.; Kreuter, Matthew; Spring, Bonnie; Cofta-Woerpel, Ludmila; Linnan, Laura; Weiner, Diane; Bakken, Suzanne; Kaplan, Cecilia Patrick; Squiers, Linda; Fabrizio, Cecilia; Fernandez, Maria

2010-01-01

425

ENVIRONMENTAL ENGINEERING  

E-print Network

ENVIRONMENTAL ENGINEERING UNDERGRADUATE HANDBOOK Cornell University Department of Biological and Environmental Engineering School of Civil and Environmental Engineering enve.cornell.edu 2013-2014 #12;Environmental Engineering 2013-2014 1 UNDERGRADUATE HANDBOOK FOR ENVIRONMENTAL ENGINEERING MISSION STATEMENT

Walter, M.Todd

426

electrical, engineering  

E-print Network

and Sustainable Solar Technologies (QESST), works with students building solar cars in Fulton Engineering's BEST barrier: room-temperature electrically powered nanolasers New mobile app enables research, education engineering materials science and engineering mechanical engineering solar energy engineering

Zhang, Junshan

427

Lower Sioux Wind Feasibility & Development  

SciTech Connect

This report describes the process and findings of a Wind Energy Feasibility Study (Study) conducted by the Lower Sioux Indian Community (Community). The Community is evaluating the development of a wind energy project located on tribal land. The project scope was to analyze the critical issues in determining advantages and disadvantages of wind development within the Community. This analysis addresses both of the Community's wind energy development objectives: the single turbine project and the Commerical-scale multiple turbine project. The main tasks of the feasibility study are: land use and contraint analysis; wind resource evaluation; utility interconnection analysis; and project structure and economics.

Minkel, Darin

2012-04-01

428

Dwarf eelgrass, Zostera japonica: a malevolent, benevolent, or benign invasive ecosystem engineer?  

EPA Science Inventory

Dwarf eelgrass, Zostera japonica, is an introduced ecosystem engineering species first reported on the US west coast in 1957. In some US Pacific Northwest estuaries its areal coverage now exceeds that of the native eelgrass species, Zostera marina. Natural resource management?s...

429

Native and Introduced Ecosystem Engineers Produce Contrasting Effects on Estuarine Infaunal Communities  

Microsoft Academic Search

Cordgrasses in the genus Spartina are good examples of ecosystem engineers that modify habitat structure in estuaries throughout the world. In San Francisco\\u000a Bay, California, USA, marshes containing native California cordgrass (Spartina foliosa) are being invaded by a hybrid (S. alterniflora × S. foliosa) formed after introduction of S. alterniflora. This study compared vegetation, sediment structure, and infaunal invertebrates in

Elizabeth D. Brusati; Edwin D. Grosholz

2006-01-01

430

Heavy Metals (Cd, Cu, Cr, Pb and Zn) in Meretrix meretrix Roding, Water and Sediments from Estuaries in Sabah, North Borneo  

ERIC Educational Resources Information Center

Concentrations of heavy metals (Cd, Cu, Cr, Pb and Zn) in tissues of Meretrix meretrix Roding (M. meretrix R.), water and sediments from two estuaries were determined. One estuary is located in an urban area of Kota Kinabalu (Likas estuary) and the other in a rural district of Kota Belud (Kota Belud estuary), where both are in Sabah, North of…

Abdullah, Mohd. Harun; Sidi, Jovita; Aris, Ahmad Zaharin

2007-01-01

431

A framework for investigating general patterns of benthic ?-diversity along estuaries  

NASA Astrophysics Data System (ADS)

The description of major patterns in beta (?) diversity is important in order to understand changes in community composition and/or richness at different spatial and temporal scales, and can interrogate processes driving species distribution and community dynamics. Human impacts have pushed many estuarine systems far from their historical baseline of rich, diverse, and productive ecosystems. Despite the ecological and social importance of estuaries, there has not yet been an attempt to investigate patterns of ?-diversity and its partitioning along estuarine systems of different continents. We aimed to evaluate if benthic assemblages would show higher turnover than nestedness in tropical than in temperate systems, if well-known impacted estuaries would show greater nestedness than less polluted systems, and to propose a conceptual framework for studying benthic macrofauna beta diversity along estuaries. We analyzed subtidal benthic macrofaunal data from estuaries in Brazil, USA and France. We estimated alpha (?), beta (?) and gamma (?) diversity for each sampling time in each system, investigated patterns of ? -diversity as multivariate dispersion and the partitioning (nestedness and replacement) of ?-diversity along each estuary. There was a decrease in the ?-diversity along marine to freshwater conditions at most of the estuaries and sampling dates. Beta diversity as multivariate dispersion showed high variability. Most of the estuaries showed a greater proportion of the ?-diversity driven by replacement than nestedness. We suggest a conceptual framework for estuaries where relatively pristine estuaries would have their ?-diversity mostly driven by replacement while impacted estuaries subjected to several anthropogenic stressors would show total nestedness or total replacement, depending on the stress.

Barros, Francisco; Blanchet, Hugues; Hammerstrom, Kamille; Sauriau, Pierre-Guy; Oliver, John

2014-08-01

432

Salt intrusion during the dry season in the Huangmaohai Estuary, Pearl River Delta, China  

NASA Astrophysics Data System (ADS)

The Huangmaohai Estuary is the most western estuary in the Pearl River Delta, China. The tide in the estuary is a mixed semi-diurnal tide. The water level fluctuation is dominated by periods of semi-diurnal tide and alternated by periods of diurnal tide. The tidal range is generally larger during diurnal tide than during semi-diurnal tide, thus the diurnal tide and the semi-diurnal tide are referred to as spring tide and neap tide, respectively, in a traditional sense. The estuary is classified as well-mixed to partially mixed in dry seasons. The salinity distribution is abnormal, since the estuary becomes more stratified during the diurnal tide and more mixed during the semi-diurnal tide. Correspondingly, salt intrusion is strong during the diurnal tide and weak during the semi-diurnal tide. Model diagnostic analyses indicate that the geometry of the estuary largely controls the variation of tidal current during the spring-neap tidal cycle, and the water exchange among the Pearl River Network plays an important role in modulating salt intrusion in the estuary. The change of the diurnal tide and the semi-diurnal tide during a spring-neap tidal cycle results in a strong tidal current during semi-diurnal tide and a weak current during the diurnal tide, which contributes to the change in mixing and salt flux in the estuary. The variation of freshwater discharged into the estuary over a spring-neap tidal cycle is controlled by the river flow distribution in the Pearl River Network and demonstrates a pattern with more freshwater inflow in the estuary during the semi-diurnal tide than that during the diurnal tide. This pattern coincides with the change in tidal mixing resulting in variations of stratification, estuarine circulation, and salt transport during the spring-neap tidal cycle. The combination of tidal action and buoyancy forcing determines the salt intrusion pattern.

Gong, Wenping; Shen, Jian; Jia, Liangwen

2013-02-01

433

FEASIBILITY STUDY OF PRESSURE PULSING PIPELINE UNPLUGGING TECHNOLOGIES FOR HANFORD  

SciTech Connect

The ability to unplug key waste transfer routes is generally essential for successful tank farms operations. All transfer lines run the risk of plugging but the cross site transfer line poses increased risk due to its longer length. The loss of a transfer route needed to support the waste feed delivery mission impacts the cost and schedule of the Hanford clean up mission. This report addresses the engineering feasibility for two pressure pulse technologies, which are similar in concept, for pipeline unplugging.

Servin, M. A. [Washington River Protection Solutions, LLC, Richland, WA (United States); Garfield, J. S. [AEM Consulting, LLC (United States); Golcar, G. R. [AEM Consulting, LLC (United States)

2012-12-20

434

Nutrient transport to the Swan-Canning Estuary, Western Australia  

NASA Astrophysics Data System (ADS)

Catchment nutrient availability in Western Australia is primarily controlled by the disposal of animal waste and the type and rate of fertilizer application, particularly on the relatively narrow (25 km wide), sandy coastal plain. Nitrogen (N) and phosphorus (P) concentrations and fluxes during the wet season of 15 tributaries, including four urban drains to the Swan-Canning Estuary, were evaluated from 1986 to 1992 and additionally concentrations only were evaluated throughout the year from 1993 to 1996. Concentrations of filtered reactive P (FRP) and total P (TP) were generally low, with the volume-weighted means for all sites being 0·06 mg l-1 and 0·12 mg l-1 respectively. The urban drains had higher TP concentrations (volume-weighted mean of 0·21 mg l-1) than the streams (0·12 mg l-1), with the high concentrations associated with particulate matter. Total inorganic N (TIN, NH4N plus NO3N) and total N (TN), which is of interest to eutrophic status of the N-limited estuary, were likewise low, compared with other developed areas having a similar climate. Both TIN and TN were higher in the urban drains (0·76 mg l-1 and 1·5 mg l-1 respectively) than the streams (0·31 mg l-1 and 1·2 mg l-1 respectively). The Avon River, which drains 98·5% of the 121 000 km2 catchment area, contributes most of the N (0·03 kg ha-1 year-1 or 65%) and a high percentage of the P (<0·01 kg ha-1estuaries. The Avon River nutrient fluxes are much less than other tributaries closer to the estuary. The coastal plain receives significantly higher rainfall (1,200 mm yearestuary. The coastal plain is also undergoing urbanization, particularly in areas adjacent to the estuary. Nutrients are subsequently available for transport during the onset of seasonal wet weather. Perennial baseflow from urban areas is an important source of nutrients. Water yield from the urban areas was high, being as much as 50% of annual rainfall. The timing of the nutrients delivered by the tributaries may be an important control on estuarine ecology.

Peters, Norman E.; Donohue, Robert

2001-09-01

435

Nutrient transport to the Swan - Canning Estuary, Western Australia  

USGS Publications Warehouse

Catchment nutrient availability in Western Australia is primarily controlled by the disposal of animal waste and the type and rate of fertilizer application, particularly on the relatively narrow (~25 km wide), sandy coastal plain. Nitrogen (N) and phosphorous (P) concentrations and fluxes during the wet season of 15 tributaries, including four urban drains to the Swan-Canning Estuary, were evaluated from 1986 to 1992 and additionally concentrations only were evaluated throughout the year from 1993 to 1996. Concentrations of filtered reactive P (FRP) and total P (TP) were generally low, with the volume-weighted means for all sites being 0.06 mg 1-1 and 0.12 mg 1-1 respectively. The urban drains had higher TP concentrations (volume-weighted mean of 0.21 mg 1-1) than the streams (0.12 mg 1-1), with the high concentrations associated with particulate matter. Total inorganic N (TIN, NH4N plus NO3N) and total N (TN), which is of interest to eutrophic status of the N-limited estuary, were likewise low, compared with other developed areas having a similar climate. Both TIN and TN were higher in the urban drains (0.76 mg 1-1 and 1.5 mg 1-1 respectively) than the streams (0.31 mg 1-1 and 1.2 mg 1-1 respectively). The Avon River, which drains 98.5% of the 121 000 km2 catchment area, contributes most of the N (0.03 kg ha-1 year-1 or 65%) and a high percentage of the P (<0.01 kg ha-1 year-1 or 32%) to the estuaries. The Avon River nutrient fluxes are much less than other tributaries closer to the estuary. The coastal plain receives significantly higher rainfall (1,200 mm year-1) and has more intense horticulture and animal production than inland areas (<300 mm year-1). Annual rainfall is seasonal, occuring primarily from May through December. The surficial aquifers on the coastal plain generally are sandy with a low nutrient retention capacity, and rapidly transmit soluble and colloidal material in subsurface flow. Ellen Brook, on the coastal plain, drains pastures treated with superphosphate and has the highest FRP (0.51 mg 1-1), TP (0.7 mg 1-1) and TN (2.1 mg 1-1) of any tributary to the estuary. The coastal plain is also undergoing urbanization, particularly in areas adjacent to the estuary. Nutrients are subsequently available for transport during the onset of seasonal wet weather. Perennial baseflow from urban areas is an important source of nutrients. Water yield from the urban areas was high, being as much as 50% of annual rainfall. The timing of the nutrients delivered by the tributaries may be an important control on estuarine ecology. Copyright ?? 2001 John Wiley and Sons, Ltd.

Peters, N.E.; Donohue, R.

2001-01-01

436

Stirling Engine Heat Pump  

NASA Astrophysics Data System (ADS)

Recent advances in the feasibility studies related to the Stirling engines and Stirling engine heat pumps which have been considered attractive due to their promising role in helping to solve the global environmental and energy problems,are reviewed. This article begins to describe the brief history of the Stirling engines and theoretical thermodynamic analysis of the Stirling cycle in order to understand several advantages on the Stirling engine. Furthermore,they could throw light on our question why the dream engines had not been promoted to practical applications during two hundred years. The present review shows that the Stirling engines with several unique advantages including 30 to 40% thermal efficiency and preferable exhaust characteristics,had been designed and constructed by recent tackling for the development of the advanced automobile and other applications using them. Based on the current state of art,it is being provided to push the Stirling engines combined with heat pumps based on the reversed Rankine cycle to the market. At present,however, many problems, especially for the durability, cost, and delicate engine parts must be enforced to solve. In addition,there are some possibilities which can increase the attractiveness of the Stirling engines and heat pumps. The review closes with suggestions for further research.

Kagawa, Noboru

437

Mechanical engineering COLLEGE of ENGINEERING  

E-print Network

Mechanical engineering COLLEGE of ENGINEERING DepartmentofMechanicalEngineering CollegeofEngineering Engineering Entrepreneur Certificate Program is a great addition to a mechanical engineering degree. The EDGE.wayne.edu/advising t engadmissions@wayne.edu Learn more online t engineering.wayne.edu/me #12;What is Mechanical Engineering? Harness

Berdichevsky, Victor

438

Assessing ecological risks within a highly industrialized estuary  

SciTech Connect

Ecological assessment (EA) was conducted for a landfill located along an industrialized river within the NY/NJ Harbor Estuary. This estuary has been subjected to intense industrial and urban development throughout the past two centuries, resulting in alterations to the Site and regional ecology. For these reasons, consideration was given to the local and regional setting, and the relatively low quantity and degraded quality of habitats that exist in proximity to the Site. The EA focused on two ecological receptor groups: (1) aquatic receptors (i.e., benthic invertebrates and small forage fish) exposed primarily through direct contact with sediments and surface water; and (2) piscivorous species (i.e., great blue heron) for whom exposure is the result of trophic transfer through dietary intakes. Estimates of accumulation in prey species of the great blue heron were derived using a simplified food web model to predict trophic transfer. The primary chemicals of potential ecological concern (COPEC) included arsenic, selenium, mercury, as well as PCBs. Based on the results of this assessment, risk to piscivorous wildlife are very low; derived hazard quotients (HQ) were below one for all COPEC. HQ greater than one were observed for direct exposures to aquatic receptors, however, the HQ determined for exposures at the Site were generally within the range of those reported for sediments and surface waters throughout the NY/NJ Harbor Estuary. In addition, numerous non-chemical stressors were identified that likely significantly affect the health and abundance of aquatic organisms. For these reasons, the Site was determined not to contribute an increased risk to ecological receptors above a regional level.

Bonnevie, N.L.; Iannuzzi, T.J. [McLaren-Hart/ChemRisk, Portland, ME (United States); Bland, J.A. [Merck and Co., Whitehouse Station, NJ (United States); Harman, C.H. [McLaren-Hart/ChemRisk, Warren, NJ (United States)

1995-12-31

439

Tsunami flooding along Tagus estuary, Portugal, the 1531 event  

NASA Astrophysics Data System (ADS)

TSUNAMI FLOODING ALONG TAGUS ESTUARY (PORTUGAL), THE 1531 EVENT The city of Lisbon one of the main towns in Europe between the XVI and XVIII centuries was severely damaged by two strong earthquakes: 1531-01-26 and 1755-11-01 and the companion tsunamis. In this study we present a re-evaluation of the data available for this event. The 26 January 1531 earthquake occurred between 4 and 5 am and was felt mainly in Lisbon and surroundings dwellings along the Tagus river estuary. The shock heavily destroyed Lisbon downtown causing approximately 1000 casualties Two foreshocks preceded the event: on the 2nd and the 7th January 1531, respectively. The maximum MSK intensity is IX, making it one of the most disastrous earthquakes in the recent history of Portugal. The historical descriptions clearly describe the observation of high waves and the ships touching the riverbed. Although, the difference between tsunamis and storms is sometimes unclear in some historical documents, in this case, the occurrence of the of the earthquake definitively states clearly excludes the hypothesis of a storm. Moreover, the king's chronicle clearly states the observation of high waves and the lack of wind. Other reports consistent with the occurrence of a tsunami are the observation of strong fluxes and refluxes in the river the division of islands into smaller ones and the observation of the riverbed. In this study we present a re-appraisal of the historical information available, a new isoseismal map and the relocation of the epicentre. Finally, we present a tsunami simulation and propagation along a section of 70 km along Tagus estuary compatible with the earthquake data and the historical accounts.

Baptista, M. A.; Miranda, J. M.; Batlo, J.; Ferreira, H.

2012-04-01

440

The Mattole River Estuary: Restoration Efforts in a Dynamic System  

NASA Astrophysics Data System (ADS)

Despite extensive scientific advancement integrating our understanding of hydrology, geomorphology, and ecology in recent decades, the application of restoration in the field has been slow to evolve. This presentation will highlight 20 years of restoration practices in the Mattole River Estuary and how these practices have informed our understanding of this complex system. The Mattole River Watershed is a 304 square-mile basin located near the Mendocino Triple Junction in a remote region of California known as the “The Lost Coast” for its rugged mountains and undeveloped coastline. In addition to numerous species of fish, mammals, and over 250 bird species, the Mattole Watershed is home to three Federally-listed Threatened salmonids: California Coastal Chinook salmon, Southern Oregon/Northern California Coasts coho salmon, and Northern California steelhead trout. The 64 mile-long river meets the Pacific Ocean at the northern end of the 64,000 acre King Range National Conservation Area (KRNCA), managed by the Bureau of Land Management (BLM). The watershed is dynamic, with some of the nation’s highest annual rainfall (mean = 158 cm/yr), naturally occurring steep slopes, erosive sedimentary geology, and frequent earthquakes. All of these factors have amplified the negative effects of extensive logging and associated road building between 1945 and 1970, which left a legacy of increased sediment loads and high water temperatures that have yet to recover to pre-disturbance levels, severely impairing riparian and aquatic habitats. Prior to major land disturbances, the Mattole estuary/lagoon was notable for its deep, thermally-stratified pools and numerous functioning north and south bank slough channels that flushed sediments from the river and received marine water. As flows decline in late spring, a sandbar closes off surface flow from the river to the Pacific Ocean, forming a lagoon, which persists until flows increase in the fall. Today, the estuary is poor habitat for all salmon and steelhead species: the water too warm, habitat cover poor, the channel lacks riparian vegetation, and only remnant, non- functioning slough channels are present. Over the last 20 years, the Mattole Salmon group has installed and monitored 12 large wood structures that have had various effects on the instream habitat and geomorphic processes that influence river and estuary dynamics. Methods of construction and hydrologic and geomorphic effects will be discussed, as will developing designs to reconnect abandon slough tributary channels.

Barber, D.; Liquori, M.

2010-12-01

441

Introduction Systems Engineering Fundamentals ENGINEERING  

E-print Network

Introduction Systems Engineering Fundamentals i SYSTEMS ENGINEERING FUNDAMENTALS January 2001;Systems Engineering Fundamentals Introduction ii #12;Introduction Systems Engineering Fundamentals iii ............................................................................................................................................. iv PART 1. INTRODUCTION Chapter 1. Introduction to Systems Engineering Management

Rhoads, James

442

Tivoli Brewery: A Feasibility Study.  

ERIC Educational Resources Information Center

This document reports on a study made to ascertain the feasibility of preserving and restoring all or part of an existing historical site -- the "Tivoli Brewery" -- as a related and integral part of the Auraria Higher Education Center. After investigation of the building's structural integrity, the condition of electrical and mechanical systems,…

More, Combs, and Burch, Denver, CO.

443

Feasibility of Ipecac Extraction Plant.  

National Technical Information Service (NTIS)

'Brazilian' ipecac is the rhizome and root portions of the low growing vine Cephaelis (Uragoga) ipecacuanha. It is the source of emetine and several other alkaloids. The report presents the results of a study undertaken to determine the feasibility of est...

E. H. Payne

1966-01-01

444

Library Data Processing Feasibility Report.  

ERIC Educational Resources Information Center

To establish the precise effects of using MARC II in West Sussex, and how it could assist the library staff were the goals of this feasibility study. It illustrates the development of the library catalog and associated systems as both realistic and practical. It indicates what kind of repercussions will be felt by the library and how it could…

Mears, M. J.; And Others

445

KE Basin water dispositioning engineering study  

SciTech Connect

This engineering study is a feasibility study of KE Basin water treatment to an acceptable level and dispositioning the treated water to Columbia River, ground through ETF or to air through evaporation.

Hunacek, G.S.; Gahir, S.S.

1994-09-23

446

Lower Columbia River and Estuary Ecosystem Restoration Program Reference Site Study: 2011 Restoration Analysis - FINAL REPORT  

SciTech Connect

The Reference Site (RS) study is part of the research, monitoring, and evaluation (RME) effort developed by the Action Agencies (Bonneville Power Administration [BPA], U.S. Army Corps of Engineers, Portland District [USACE], and U.S. Bureau of Reclamation) in response to Federal Columbia River Power System (FCRPS) Biological Opinions (BiOp). While the RS study was initiated in 2007, data have been collected at relatively undisturbed reference wetland sites in the LCRE by PNNL and collaborators since 2005. These data on habitat structural metrics were previously summarized to provide baseline characterization of 51 wetlands throughout the estuarine and tidal freshwater portions of the 235-km LCRE; however, further analysis of these data has been limited. Therefore, in 2011, we conducted additional analyses of existing field data previously collected for the Columbia Estuary Ecosystem Restoration Program (CEERP) - including data collected by PNNL and others - to help inform the multi-agency restoration planning and ecosystem management work underway in the LCRE.

Borde, Amy B.; Cullinan, Valerie I.; Diefenderfer, Heida L.; Thom, Ronald M.; Kaufmann, Ronald M.; Zimmerman, Shon A.; Sagar, Jina; Buenau, Kate E.; Corbett, C.

2012-05-31

447

Microphytobenthos interannual variations in a north-European estuary (Loire estuary, France) detected by visible-infrared multispectral remote sensing  

NASA Astrophysics Data System (ADS)

Estuarine intertidal sediments are colonized by photosynthetic microorganisms grouped under the generic term of microphytobenthos (MPB). These microbial assemblages form transient biofilms at the sediment surface and have important ecosystem functions. MPB biofilms are well known to exhibit high microscale patchiness whereas meso- and macroscale spatio-temporal structures are little known. In this work, satellite remote sensing was used to map MPB assemblages at such scales. MPB interannual distribution was investigated in the poly- and mesohaline domain of the north-European estuary (Loire estuary), using a multispectral SPOT image time series (1991-2009). The Normalized Difference Vegetation Index (NDVI) was calculated from two SPOT channels, XS2 and XS3, (red and near-infrared wavelengths, respectively). MPB biofilms were identified by NDVI values between 0 and 0.3. At the scale of the whole intertidal area, the results showed that MPB biofilms in the Loire estuary exhibited perennial structures in both the polyhaline and mesohaline sectors, occupying nearly 90% of the mudflat surfaces. MPB biofilm density was closely associated with intertidal position, with thicker biofilms developing mostly in the upper and middle shore, and formed kilometric longitudinal structures parallel to the shoreline. Mean NDVI values showed a strong positive correlation with mean seasonal air temperature (? = 0.714, p < 0.05 in the polyhaline domain and ? = 0.810, p < 0.05 in the mesohaline domain), with a strong correlation in the upper intertidal mudflat (between +3 and 4 m isobaths). Negative wind effect was mainly detected in the upper intertidal areas, particularly between the +3 and 4 m isobaths (? = -0.810, p < 0.05 in the polyhaline domain and ? = -0.910 in the mesohaline).

Benyoucef, Ismaïl; Blandin, Elodie; Lerouxel, Astrid; Jesus, Bruno; Rosa, Philippe; Méléder, Vona; Launeau, Patrick; Barillé, Laurent

2014-01-01

448

Modelling and mass balance assessments of nutrient retention in a seasonally-flowing estuary (Swan River Estuary, Western Australia)  

NASA Astrophysics Data System (ADS)

An integrated mass balance and modelling approach for analysis of estuarine nutrient fluxes is demonstrated in the Swan River Estuary, a microtidal system with strong hydrological dependence on seasonal river inflows. Mass balance components included estimation of gauged and ungauged inputs to the estuary and losses to the ocean (outflow and tidal exchange). Modelling components included estimation of atmospheric (N fixation, denitrification) and sediment-water column nutrient exchanges. Gross and net denitrification derived using two independent methods were significantly correlated ( r2 = 0.49, p < 0.01) with net rates averaging 40% of gross. Annual nitrogen (N) and phosphorus (P) loads from major tributaries were linearly correlated with annual freshwater discharge and were 3-fold higher in wet years than in dry years. Urban drains and groundwater contributed, on average, 26% of N inputs and 19% of P inputs, with higher relative contributions in years of low river discharge. Overall, ungauged inputs accounted for almost 35% of total nitrogen loads. For N, elevated loading in wet years was accompanied by large increases in outflow (7x) and tidal flushing (2x) losses and resulted in overall lower retention efficiency (31%) relative to dry years (70%). For P, tidal flushing losses were similar in wet and dry years, while outflow losses (4-fold higher) were comparable in magnitude to increases in loading. As a result, P retention within the estuary was not substantially affected by inter-annual variation in water and P loading (ca. 50% in all years). Sediment nutrient stores increased in most years (remineralisation efficiency ca. 50%), but sediment nutrient releases were significant and in some circumstances were a net source of nutrients to the water column.

Robson, Barbara J.; Bukaveckas, Paul A.; Hamilton, David P.

2008-01-01

449

Artiflcial Intelligence Technologies in Complex Engineering Design  

Microsoft Academic Search

Abstract: COMPUTATIONAL ENGINEERING AND DESIGN CENTERSCHOOL OF ENGINEERING SCIENCESDoctor of PhilosophyArtificial Intelligence Technologies in Complex Engineering Designby Yew Soon OngEngineering design optimization is an emerging technology whose application bothtends to shorten design-cycle time and finds new designs that are not only feasible,but also nearer to optimum, based on specified design criteria. Its gain in attentionin the field of complex designs

Yew Soon Ong

2002-01-01

450

Engine system assessment study using Martian propellants  

NASA Technical Reports Server (NTRS)

A feasibility study was performed that identified and characterized promising chemical propulsion system designs that utilize two or more of the propellant combinations: LOX/H2, LOX/CH4 and LOX/CO. The engine systems examined focused on the usage of common subsystem/component hardware where feasible. From the evaluation baseline employed, tripropellant MTV LOX cooled and bipropellant LEV and MEV engine systems are identified.

Pelaccio, D.; Jacobs, M.; Collins, J.; Scheil, C.; Meyer, M.

1992-01-01

451

Engine system assessment study using Martian propellants  

NASA Astrophysics Data System (ADS)

A feasibility study was performed that identified and characterized promising chemical propulsion system designs that utilize two or more of the propellant combinations: LOX/H2, LOX/CH4 and LOX/CO. The engine systems examined focused on the usage of common subsystem/component hardware where feasible. From the evaluation baseline employed, tripropellant MTV LOX cooled and bipropellant LEV and MEV engine systems are identified.

Pelaccio, D.; Jacobs, M.; Collins, J.; Scheil, C.; Meyer, M.

1992-07-01

452

Numerical Simulation of phytoplankton productivity in partially mixed estuaries  

USGS Publications Warehouse

A two-dimensional steady-state model of light-driven phytoplankton productivity and biomass in partially mixed estuaries has been developed. Effects of variations in river flow, suspended sediment concentration, phytoplankton sinking, self-shading and growth rates on distributions of phytoplankton biomass and productivity are investigated. Numerical simulation experiments show that biomass and productivity are particularly sensitive to variations in suspended sediment concentrations typical of natural river sources and to variations in loss rates assumed to be realistic but poorly known for real systems. Changes in the loss rate term within the range of empirical error (such as from dark bottle incubation experiments) cause phytoplankton biomass to change by a factor of two. In estuaries with adequate light penetration in the water column, it could be an advantage for phytoplankton to sink. Species that sink increase their concentration and form a phytoplankton maximum in a way similar to the formation of the estuarine turbidity maximum. When attenuation is severe, however, sinking species have more difficulty in maintaining their population. ?? 1984.

Peterson, D.H.; Festa, J.F.

1984-01-01

453

Geochemical phases of metals in Hudson River estuary sediments  

SciTech Connect

Bottom sediment samples were collected from six location along a section of the Hudson River Estuary, 5.3 to 82.7 km from the ocean. These samples were analyzed for particle and, due to the bimodal distribution of the sediment, were seperated into two size fractions, fine (<7.8 um) and coarse (7.8-62 um). These fractions were subject to a sequential chemical phase extraction procedure to differenciate the ion exchangeable, carbonate, metallic oxide coating, and organic phases. The extracted phases were analyzed with an inductively coupled plasma atomic emission spectrophotometer for Cd, Co, Cc, Cu, Fe, Ni, Pb, and Zn. Metals were found to be associated largely with fine particle-size fraction. The concentration of fine particles (especially the <2 um size mode within the fine fraction) is a crucial in influencing overall metal content. This is evidenced by strong correlations between the <2 {mu}m or clay mode and concentrations in the metallic-oxide coating phase. Various metal/metal relationships exist among the phases and fractions studied and are highlighted by strong correlations, such as Ni and Zn, and Cu and Cd. The trends associated among the metal and mud concentrations are significant in terms of assessing the bioavailability of heavy metals within the river and estuary system, and as a result, provide valuable insight into the ultimate fate of pollutants which are introduced to this unique environment. 24 refs., 5 figs., 2 tabs.

Stamoulis, S.; Gibbs, R.J.; Menon, M.G. [Univ. of Delaware, Newark, DE (United States)] [Univ. of Delaware, Newark, DE (United States)

1996-08-01

454

Environmental flow assessments in estuaries related to preference of phytoplankton  

NASA Astrophysics Data System (ADS)

We developed an approach to assess environmental flows in estuaries related to preference of phytoplankton considering the complex relationship between hydrological modification and biomass in ecosystems. As a first step, a relationship was established between biomass requirements for organisms of primary and higher nutritional levels based on the principle of nutritional energy flow of ecosystem. Then, diagnostic pigments were employed to represent phytoplankton community biomass, which indicated competition between two groups of phytoplankton in the biochemistry process. Considering empirical relationships between diagnostic pigments and critical environmental factors, responses of biomass to river discharges were established based on a convection-diffusion model by simulating distributions of critical environmental factors under action of river discharges and tide currents. Consequently, environmental flows could be recommended for different requirements of fish biomass. In the case study in the Yellow River estuary, May and October were identified as critical months for fish reproduction and growth during dry years. Artificial hydrological regulation strategies should carefully consider the temporal variations of natural flow regime, especially for a high-amplitude flood pulse, which may cause negative effects on phytoplankton groups and higher organism biomass.

Yang, Z. F.; Sun, T.; Zhao, R.

2014-01-01

455

Selenium in sediments and biota from estuaries of southwest England.  

PubMed

Selenium concentrations have been measured in sediment, fucoid macroalgae and macroinvertebrates from four estuaries of SW England (Yealm, Plym, Looe, Fal). Sediment concentrations ranged from about 0.4 ?g g(-1) in the Yealm to 1.49 ?g g(-1) at one site in the Plym. Concentrations in Fucus vesiculosus (0.05-0.31 ?g g(-1)) and F. ceranoides (0.05-0.51 ?g g(-1)) were significantly lower than corresponding concentrations in sediment but there was no correlation between algal and sediment concentrations. Selenium concentrations in Littorina littorea (~4 ?g g(-1)), Hediste diversicolor (2.82-12.68 ?g g(-1)), Arenicola marina (~17 ?g g(-1)) and Scrobicularia plana (1.18-6.85 ?g g(-1)) were considerably higher than concentrations in macroalga or sediment, suggesting that Se is effectively accumulated from the diet. Although Se concentrations in some invertebrates exceed toxicity thresholds for the diet of predacious birds and fish, no specific evidence for Se toxicity exists in these estuaries. PMID:23773950

Turner, Andrew

2013-08-15

456

Dissolved oxygen in lower Hudson Estuary: 1978--93  

SciTech Connect

During summer months, dissolved oxygen (DO) concentrations in the lower Hudson estuary were usually lower than atmospheric equilibrium values. Distributions of DO along the axis of the estuary can be described by three general characteristics. Firstly, surface and bottom values lie on a single trend when plotted against salinity. Secondly, maximum DO concentrations were observed 50--75 km upstream of Manhattan at salinities off 5--15 ppt. Thirdly, the lowest DO concentrations were observed near Manhattan, New York, at salinities of 15--25 ppt and vary systematically with freshwater discharge rate. Minimum DO concentrations during times of similar freshwater discharge were substantially lower for water samples collected between 1978 and 1984 than for those collected between 1989 and 1993. These two periods were also distinguished by occurrences of intense phytoplankton blooms that produced supersaturated DO concentrations at salinities of 5--15 ppt for the period of 1989 to 1993. The increase in the minimum DO concentration in the water near Manhattan is probably in response to improved wastewater treatment at Passaic Valley, NJ; North River, NY; and other wastewater-treatment facilities.

Clark, J.F.; Simpson, H.J. [Columbia Univ., Palisades, NY (United States). Lamont-Doherty Earth Observatory; Bopp, R.F. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Earth and Environmental Science; Deck, B.L. [Univ. of California at San Diego, La Jolla, CA (United States). Scripps Institution of Oceanography

1995-10-01

457

Mathematical simulation of sediment and radionuclide transport in estuaries  

SciTech Connect

The finite element model LFESCOT (Flow, Energy, Salinity, Sediment and Contaminant Transport Model) was synthesized under this study to simulate radionuclide transport in estuaries to obtain accurate radionuclide distributions which are affected by these factors: time variance, three-dimensional flow, temperature, salinity, and sediments. Because sediment transport and radionuclide adsorption/desorption depend strongly on sizes or types of sediments, FLESCOT simulates sediment and a sediment-sorbed radionuclide for the total of three sediment-size fractions (or sediment types) of both cohesive and noncohesive sediments. It also calculates changes of estuarine bed conditions, including bed elevation changes due to sediment erosion/deposition, and three-dimensional distributions of three bed sediment sizes and sediment-sorbed radionuclides within the bed. Although the model was synthesized for radionuclide transport, it is general enough to also handle other contaminants such as heavy metals, pesticides, or toxic chemicals. The model was checked for its capability for flow, water surface elevation change, salinity, sediment and radionuclide transport under various simple conditions first, confirming the general validity of the model's computational schemes. These tests also revealed that FLESCOT can use large aspect ratios of computational cells, which are necessary in handling long estuarine study areas. After these simple tests, FLESCOT was applied to the Hudson River estuary between Chelsea and the mouth of the river to examine how well the model can predict radionuclide transport through simulating tidally influenced three-dimensional flow, salinity, sediment and radionuclide movements with their interactions.

Onishi, Y.; Trent, D.S.

1982-11-01

458

High frequency ocean acoustic tomography observation at coastal estuary areas  

NASA Astrophysics Data System (ADS)

The ocean acoustic tomography (OAT) technique can obtain oceanographic information and has received much interest. High frequency OAT (in a narrow kHz range) can be used for small and confined areas, such as estuaries and bays, with complicated hydrological conditions. In this study, we investigate the application of high-frequency reciprocal transmission OAT to assess the sound speed, temperature, and current field in the Xiamen sea area using computer simulations and sea experiments. Based on the temperature data obtained from remote sensing and the predefined stream function, high frequency OAT is employed to reconstruct the two-dimensional sound speed, temperature, and current fields of a 1.2km×1.2km small-scale region. The correlation coefficient of the computer inversion result and the original data is higher than 0.8. The result shows that increasing the number of acoustic stations decreases the influence of the travel-time errors in high frequency OAT; however, excessively increasing the number of stations could not significantly improve the inversion accuracy. Furthermore, this method has been tested by a sea experiment on monitoring the shallow water temperature of Wuyuan Bay. High frequency OAT might provide an effective method for temperature and current observation at coastal estuary areas.

Zhao, Zongxi; Zhang, Yu; Yang, Wuyi; Chen, Dongsheng

2012-11-01

459

Interaction between suspended sediment and tidal amplification in the Guadalquivir Estuary  

NASA Astrophysics Data System (ADS)

Water level records at two stations in the Guadalquivir Estuary (Spain), one near the estuary mouth (Bonanza) and one about 77 km upstream (Sevilla), have been analysed to study the amplification of the tide in the estuary. The tidal amplification factor shows interesting temporal variation, including a spring-neap variation, some extreme low values, and especially the anomalous behaviour that the amplification factor is larger during a number of periods. These variations are explained by data analysis combined with numerical and analytical modelling. The spring-neap variation is due to the quadratic relation between the bottom friction and the tidal flow velocity. The river flood events are the direct causes of the extreme low values of the amplification factor, and they trigger the non-linear interaction between the tidal flow and suspended sediment transport. The fluvial sediment input during a river flood causes high sediment concentration in the estuary, up to more than 10 g/l. This causes a reduction of the effective hydraulic drag, resulting in stronger tidal amplification in the estuary for a period after a river flood. After such an event the tidal amplification in the estuary does not always fall back to the same level as before the event, indicating that river flood events have significant influence on the long-term development of this estuary.

Wang, Zheng Bing; Winterwerp, Johan C.; He, Qing

2014-08-01

460

Interaction between suspended sediment and tidal amplification in the Guadalquivir Estuary  

NASA Astrophysics Data System (ADS)

Water level records at two stations in the Guadalquivir Estuary (Spain), one near the estuary mouth (Bonanza) and one about 77 km upstream (Sevilla), have been analysed to study the amplification of the tide in the estuary. The tidal amplification factor shows interesting temporal variation, including a spring-neap variation, some extreme low values, and especially the anomalous behaviour that the amplification factor is larger during a number of periods. These variations are explained by data analysis combined with numerical and analytical modelling. The spring-neap variation is due to the quadratic relation between the bottom friction and the tidal flow velocity. The river flood events are the direct causes of the extreme low values of the amplification factor, and they trigger the non-linear interaction between the tidal flow and suspended sediment transport. The fluvial sediment input during a river flood causes high sediment concentration in the estuary, up to more than 10 g/l. This causes a reduction of the effective hydraulic drag, resulting in stronger tidal amplification in the estuary for a period after a river flood. After such an event the tidal amplification in the estuary does not always fall back to the same level as before the event, indicating that river flood events have significant influence on the long-term development of this estuary.

Wang, Zheng Bing; Winterwerp, Johan C.; He, Qing

2014-10-01

461

A Numerical Study of Local Variations in Tidal Regime of Tagus Estuary, Portugal  

PubMed Central

Tidal dynamics of shallow estuaries and lagoons is a complex matter that has attracted the attention of a large number of researchers over the last few decades. The main purpose of the present work is to study the intricate tidal dynamics of the Tagus estuary, which states as the largest estuary of the Iberian Peninsula and one of the most important wetlands in Portugal and Europe. Tagus has large areas of low depth and a remarkable geomorphology, both determining the complex propagation of tidal waves along the estuary of unknown manner. A non-linear two-dimensional vertically integrated hydrodynamic model was considered to be adequate to simulate its hydrodynamics and an application developed from the SIMSYS2D model was applied to study the tidal propagation along the estuary. The implementation and calibration of this model revealed its accuracy to predict tidal properties along the entire system. Several model runs enabled the analysis of the local variations in tidal dynamics, through the interpretation of amplitude and phase patterns of the main tidal constituents, tidal asymmetry, tidal ellipses, form factor and tidal dissipation. Results show that Tagus estuary tidal dynamics is extremely dependent on an estuarine resonance mode for the semi-diurnal constituents that induce important tidal characteristics. Besides, the estuarine coastline features and topography determines the changes in tidal propagation along the estuary, which therefore result essentially from a balance between convergence/divergence and friction and advection effects, besides the resonance effects. PMID:24312474

Dias, Joao Miguel; Valentim, Juliana Marques; Sousa, Magda Catarina

2013-01-01

462

Dissolved organic carbon in the freshwater tidal reaches of the Schelde estuary  

NASA Astrophysics Data System (ADS)

To unravel the factors that regulate DOC dynamics in the freshwater tidal reaches of the Schelde estuary, DOC concentration and biodegradability were monitored in the upper Schelde estuary and its major tributaries. Although the Schelde estuary possesses a densely populated and industrialized catchment, our data suggest that the bulk of DOC in the freshwater tidal reaches is not derived from waste water. This was concluded from the low biodegradability of DOC (on average 9%), DOC concentrations that are close to the mean for European rivers (4.61 mg l -1) and the absence of an inverse relationship between DOC and discharge. Most DOC originating from waste water being discharged in tributaries of the estuary appears to be remineralised before these tributaries reach the main estuary. Although dense phytoplankton blooms were observed in the upper estuary during summer (up to 700 ?g chl a l -1), these blooms did not appear to produce large quantities of DOC in the freshwater tidal reaches as DOC concentrations were low when phytoplankton biomass was high. The fact that DOC concentrations were high in winter and decreased in summer suggests a predominantly terrestrial source of DOC in the freshwater tidal reaches of the Schelde estuary.

Muylaert, Koenraad; Dasseville, Renaat; De Brabandere, Loreto; Dehairs, Frank; Vyverman, Wim

2005-09-01

463

Accumulation of Phosphorus and Heavy Metals in the Swan-Canning Estuary, Western Australia  

NASA Astrophysics Data System (ADS)

Accumulation rates of P and of Zn, Cd, Pb and Cu were measured in sediment cores from the Swan-Canning Estuary in Western Australia. The main sources of P in sediments are catchments of the major tributaries Ellen Brook and Avon River. Since 1940, anthropogenic P has increased about five times in sediments of Ellen Brook and has almost trebled in sediments of the estuary. Records show that since 1940 dissolved inorganic P in the estuary has increased between two and three times. Though dissolved inorganic P appears to be conservatively mixed in the estuary, sediment inventories suggest that a significant part of the input of P is retained in the estuary. A combination of high concentrations of dissolved P in Ellen Brook and large fluxes of particulate matter from the Avon River could explain this. Concentrations of Zn, Cd, Pb and Cu in sediments have risen significantly since colonial settlement and, unlike P concentrations, have been dominated by inputs from sources near the estuary. Vertical distributions of metals in sediment cores from the estuary suggest that, historically, concentrations of Zn and Cd started increasing first, followed by Cu and then P and Pb.Acid extractable Pb, unlike Zn, Cd and Cu, in surface sediments is greater than expected from equilibration with the water column. This is attributed to the presence of particulate Pb-oxides from road runoff.

Gerritse, R. G.; Wallbrink, P. J.; Murray, A. S.